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COO-1U69-0102 


A  TRICOLOR  CARTOGRAPH 

by 
William  J.  Kubitz 


SEPTEMBER,  I968 


DEPARTMENT  OF  COMPUTER  SCIENCE  •  UNIVERSITY  OF  ILLINOIS  •   URBANA,  ILLINOIS 


Report  Wo.  282 


A  TRICOLOR  CARTOGRAPH  * 
by 
William  J.  Kubitz 


September,  I968 


Department  of  Computer  Science 
University  of  Illinois 
Urbana,  Illinois  6l801 


*  Submitted  in  partial  fulfillment  for  the  Doctor  of  Philosophy  Degree 

in  Electrical  Engineering,  at  the  University  of  Illinois,  September,  1968, 


A  TRICOLOR  CARTOGRAPH 


William  John  Kubitz,  Ph.D. 

Department  of  Electrical  Engineering 

University  of  Illinois,  1968 


A  system  for  coloring  the  interior  of  closed  boundaries  on  a 
television-like  display  is  described.   The  coloring  is  accomplished  in 
a  semi-automatic  manner  by  using  a  light  pen  to  indicate  any  point  on 
the  interior  of  the  boundary.   Given  any  interior  point,  the  system  will 
color  all  or  most  of  the  entire  interior  area  automatically.   The  colors 
are  chosen  by  the  operator  from  red,  blue,  green  and  their  combinations. 
Local  writing  and  erasing  on  the  color  display  is  also  allowed.   The 
system  is  a  self-contained  display  console  and  does  not  rely  on  the 
back-up  of  a  general  purpose  digital  computer.   Boundaries  may  be  input 
directly  be  means  of  the  light  pen  or  by  a  television  camera  or  a  flying 
spot  scanner.   A  discussion  of  the  problems  associated  with  the  automatic 
coloring  of  closed  bounded  areas  is  given. 


Ill 

ACKNOWLEDGMENT 

The  author  wishes  to  express  his  appreciation  to  Professor 
W.  J.  Poppelbaum  for  suggesting  the  overall  system  as  well  as  his 
advice  and  guidance,  to  the  members  of  the  Hardware  Research  Group  for 
their  helpful  discussions,  to  Carla  Donaldson  for  the  typing  and  to  the 
Drafting  Department  of  the  Department  of  Computer  Science  for  making 
the  drawings . 


IV 


TABLE   OF  CONTENTS 

Page 

1.  Introduction  1 

2.  The  Problem  of  Coloring 6 

2.1  Theoretical  Requirements   6 

2.2  Practical  Requirements   8 

3-   Realizable  Solutions  and  Restrictions   9 

3.1  The  Memory 9 

3.2  The  Processor 15 

3.3  The  Display 23 

4.  Description  of  System 24 

4.1  Brief  Review  of  Television  Concepts  24 

k.2     Physical  Description   26 

k .  3  The  Pen ■ 28 

k.k     The  Display 30 

4.5  The  Memory 31 

k.6     The  Processor 33 

k.6.1     The  Total  Erase  Operation 33 

4.6.2  The  Pen  Modes 33 

4.6.3  The  Coloring  Operation 34 

5.  Discussion  of  Results,  Suggested  Improvements  and  Conclusions  48 

APPENDIX 54 

BIBLIOGRAPHY   108 

VITA 109 


V 

LIST  OF  FIGURES 

Figure  Page 

1.  The  Tricolor  Cartograph  3 

2.  An  Automatically  Colored  Figure  5 

3.  Open  Boundaries  and  Multiply  Connected  Regions   7 

4.  Scanning  Methods   17 

5.  Boundary  and  Pen  Tracing 19 

6.  Problem  Boundaries   21 

7.  Tricolor  Cartograph  27 

8.  Tricolor  Cartograph  Block  Diagram  29 

9.  Top  and  Bottom  Point  Location 36 

10.  Left  and  Right  Point  Location 37 

11.  Coloring  the  Entire  Figure   3^ 

12.  Timing  Diagram  for  Coloring  Operation 40 

13-   Errors  in  Finding  the  Right  and  Left  Points 44 

14.  Simplified  Diagram  of  Coloring  Logic   47 

15.  The  Bleeding  Problem 49 

16.  Leakage  Through  a  Gap 51 

17.  Control  and  Video  Logic 56 

18.  Coloring  Logic 60 

19.  Pen  Preamplifier  1469-121 71 

20.  Counter  Buffer  1469-133   72 

21.  Horizontal  Counter  1469-134   73 

22.  Dual  9-Bit  Register  1469-135  74 

23.  8-Bit  Register  and  Coincidence  1469-136   75 

24.  R-S  Flip  Flop  1469-137 76 


VI 


Figure  Page 

25-   Vertical  Counter  1469-138 ; 77 

26.  9-Bit  Register  and  Coincidence  1469-139  78 

27.  Switch  Matrix  1469-140   79 

28.  2-Bit  Coincidence  and  R-S  Flip  Flop  l469-l4l 80 

29.  Total  Erase  Control  1469-145   8l 

30.  Level  Shifter  1469-156   82 

31.  One  Shot  Buffer  1469-159 83 

32.  General  2- Input  Nand  l469-l6l  84 

33-   General  3- Input  Nand  1469-162  85 

34.  Switch  Filter  1469-173  86 

35.  Logic  to  Video  Converter  1469-175  87 

36.  Indicator  1469-176   88 

37.  Video  to  Logic  Converter  1469-177A  89 

38.  +1  Volt  Power  Supply /Mode  Switch  1469-178 90 

39-  Pen  Shaper  and  Gate  1469-179 91 

40.  3- Input  Video  Adder  1469-180   92 

41.  General  4- Input  Nand  l469-l8l-20   93 

42.  General  J-K  Flip  Flop  l469-l8l-70   9^ 

43.  Voltage  Controlled  Oscillator  1469-184  95 

44.  Main  Junction  Box 96 

45.  Display  Junction  Box 97 

46.  Circuit  Breaker  Panel   98 

47.  Modular  Power  Supplies   99 

48.  Switch  Panel 100 

49.  Cable  Details 101 


-1- 

1.    INTRODUCTION 

In  recent  years  great  interest  has  developed  in  the  area  of 
graphical  displays  and  graphical  display  systems.   This  interest  has 
resulted  primarily  from  the  increasing  use  of  large  digital  computers 
for  information  processing.  Because  these  computers  are  capable  of  gen- 
erating large  amounts  of  information  at  high  rates,  it  has  become  neces- 
sary to  search  for  means  of  information  display  which  can  more  nearly 
match  their  speed.   In  addition,  there  is  a  continual  search  for  some 
better  means  of  communication  between  man  and  his  machines  and  it  is 
thought  that  some  improvement  can  be  obtained  by  the  use  of  visual  display 
techniques.   A  cathode  ray  tube  display  is  probably  the  most  common  type 
in  use  today.   However,  there  are  many  other  types  in  current  use  ranging 
from  small  arrays  of  light  bulbs  to  large  screen  types  involving  pro- 
jection techniques.   Although  most  displays  are  black  and  white  in  nature, 
a  few  do  utilize  color.   Often,  the  additional  complexity  of  color  is 
not  considered  worthwhile  for  a  given  application.   However,  color  will 
probably  become  more  popular  in  the  future  when  some  of  the  technical 
problems  associated  with  its  use  are  overcome. 

For  displays  associated  with  computers,  until  recently  the 
common  practice  was  to  operate  the  display  directly  from  the  computer. 
This  technique  becomes  troublesome  when  the  amount  of  information  on  the 
display  becomes  large  because  considerable  computing  time  and  memory 
space  are  utilized  just  to  regenerate  the  display.   With  the  advent  of 
the  time-sharing  concept  for  efficiently  and  conveniently  utilizing 
large  computers,  some  consider  it  only  natural  that  each  remote  station 
have  a  display.   Thus,  the  recent  trend  has  been  toward  having  a  local 
buffer  store  associated  with  the  display  unit.   Even  more  recently,  there 


appears  to  be  a  return  to  a  raster-scan  type  display  in  c 

character  generation  type  scan  currently  in  use.   The  reasons  for  these 

changes  are  partly  technological  and  partly  practical.   Practically, 

they  are  a  result  of  the  desire  to  present  more  data  and  posess  more 

versitility  in  the  display  format.   Technologically,  they  are  the  result 

of  the  development  of  high  density  storage  at  a  reasonable  cost  and 

recognition  of  the  already  advanced  state  of  standard  television  techniques, 

Concurrent  "with  and  in  association  with  these  recent  developments 
in  computer  displays  there  has  been  an  upsurge  of  interest  in  specilaized 
digital  systems  which  although  lacking  the  versitility  of  the  general 
purpose  computer,  perform  some  specialized  operations  much  more  simply 
and  more  efficiently  than  the  general  purpose  machine.   Quite  probably 
the  future  will  bring  many  specialized  "computers",  some  of  which  will 
have  displays  associated  with  them  and  most  of  which  will  be  connected 
to  a  large  central  machine  which  can  be  called  upon  in  the  few  instances 
when  its  use  is  required. 

The  Tricolor  Cartograph  (Figure  l)  is  a  specialized  display 
system  which  is  restricted  in  its  operations.   It  is  self-contained  and 
is  not  associated  with  a  general  purpose  digital  computer.   It  consists 
of  a  color  display  unit  with  a  light  pen  and  associated  control  buttons. 
The  operator  sits  in  front  of  the  display  and  uses  the  light  pen  and 
buttons  to  perform  certain  operations.   The  operations  which  can  be 
performed  are:   writing  on  the  display  with  the  pen  in  choice  of  color, 
erasing  from  the  display  with  the  pen  in  choice  of  color,  drawing  or 
erasing  closed  outlines  on  the  display  with  the  pen  (in  white),  totally 
erasing  any  color  or  all  outlines  from  the  display  and  designating  the 
interior  of  any  closed  outline  which  is  to  be  colored-in  with  a  previously 


-3- 


Figure  1.   The  Tricolor  Cartograph 


-U- 

selected  color.   The  color  information  which  is  displayed  is  stored 

a  video  signal  on  a  magnetic  disc.   Figure  2  shows  an  example  of  a  figure 

which  has  been  automatically  colored  on  the  Tricolor  Cartograph. 

Thus,  the  Tricolor  Cartograph  is  a  color  graphical  display 
system  with  self  contained  storage  which  can  perform  a  few  specialized 
operations  independently  of  a  central  computer  system.   In  particular, 
it  can  relieve  a  central  processor  from  the  duties  of  the  storage  of 
graphical  information  and  the  coloring  of  large  irregular  areas. 

There  are  many  possible  uses  for  a  system  which  can  perform 
automatic  coloring.   Some  possible  areas  of  use  are  air  traffic  control, 
radar,  map  layout,  printed  circuit  mat  layout,  pictorial  computer  simu- 
lation and  sketching.   It  may  be  possible  some  day  for  an  artist  to 
"paint"  a  picture  on  such  a  display  and  then  obtain  a  color  reproduction 
from  a  color  facsimile  machine. 


■5- 


Figure  2.   An  Automatically  Colored  Figure 


-f  - 


2.    THE  PROBLEM  OF  COLOR] 

2.1  Theoretical  Requirements 

In  order  to  color  the  interior  of  a  figure  or  a  part  of  a 
figure,  certain  information  about  the  figure  must  be  known;  namely,  the 
color  and  which  area  is  to  be  colored. 

The  color  is  a  matter  of  choice  for  the  operator.   Color  is 
characterized  by  two  quantities,  the  hue  and  the  saturation.  Hue  pertai 
to  the  actual  color  and  saturation  to  the  shading  or  grayness  of  the  hue. 
Of  course,  both  of  these  are  arbitrary  choices  and  vary  over  a  fairly 
large  continuous  range  (blue  to  red,  white  to  black).   In  a  practical 
system  it  is  usually  necessary  to  place  limitations  on  this  range. 

The  area  to  be  colored  is  defined  by  a  boundary.   If  the 
boundary  is  not  closed  or  if  it  bounds  a  multiply  connected  region, 
additional  information  is  required  in  order  to  define  what  is  to  be 
colored.   Thus,  the  following  rules  are  established  for  the  purpose  of 
discussion:   If  the  boundary  is  not  closed,  it  is  assumed  that  both  the 
inside  and  outside  are  to  be  colored.   The  outside  consists  of  all  the 
area  within  the  next  largest  closed  boundary  in  the  case  of  multiple 
boundaries  or  the  whole  plane  if  there  are  none.   In  the  case  of  multiple 
connected  regions,  the  coloring  takes  place  only  in  the  region  designated 
and  does  not  cross  into  an  adjacent  region,  unless  of  course  there  is  a 
gap  in  the  boundary.   To  put  it  simply,  the  coloring  covers  the  largest 
area  with  a  closed  boundary  and  does  not  cross  closed  boundaries.   These 
cases  are  illustrated  in  Figure  3-   In  theory,  the  solution  to  this 
problem  is  simple:   Given  an  initial  point  known  to  be  inside  the  boundary, 
color  all  adjacent  points  not  on  or  beyond  a  boundary.  Although  this 


-7- 


A.  Open    Boundary 


B.  Multiply   Connected 


Figure  3.   Open  Boundaries  and  Multiply  Connected  Regions 


method  can  be  realized,  it  is  not  simple  or  practical  for  large  nu' 
of  points.   Because  of  this,  other  methods  were  explored.   These  are 
discussed  in  Section  3« 

Thus,  from  a  theoretical  point  of  view  the  following  information 
must  be  known:   the  closed  boundary,  the  hue,  the  saturation  and  sc 
point  which  determines  in  some  way  which  side  of  the  boundary  the  coloring 
is  to  begin  on  (an  initial  point). 

2.2  Practical  Requirements 

At  this  point  in  the  discussion  four  requirements  of  the 
coloring  system  have  been  stated.   The  color  (hue  and  saturation)  must 
be  known,  the  closed  boundary  must  be  known  and  a  defining  point  must  be 
given.   In  order  to  accomplish  reasonable  automatic  coloring  in  an 
electronic  system,  some  other  requirements  must  be  added.   First,  the 
actual  coloring  must  be  accomplished  in  a  reasonable  time  (0.1  -  0.2 
seconds  for  example).   Second,  it  must  be  accomplished  at  a  reasonable 
cost.   Third,  the  coloring  operation  should  be  as  automatic  as  possible, 
requiring  a  minimum  number  of  manipulations  by  the  operator.   Fourth, 
the  resolution  and  registration  of  the  colored  area  and  the  outline  should 
be  good. 

Thus,  there  are  four  theoretical  requirements  and  four  practical 
requirements  which  must  be  satisfied  in  order  to  accomplish  reasonable 
automatic  coloring. 


-9- 


3.    REALIZABLE  SOLUTIONS  AND  RESTRICTIONS 

In  addition  to  the  theoretical  and  practical  requirements  of 
the  coloring  operation,  in  a  realizable  system  it  may  be  necessary  to 
impose  certain  restrictions  depending  on  the  choice  of  memory,  control 
and  display  units  to  be  used.   In  the  following  sections  these  restric- 
tions are  discussed  with  regard  to  particular  choices  of  the  memory, 
display  and  control. 

3-1  The  Memory 

In  order  to  attain  what  is  commonly  called  a  "flicker  free" 
display  it  is  necessary  that  the  memory  be  continuously  read  out  and 
displayed.   This  requirement  can  frequently  be  relaxed  to  some  extent  by 
utilizing  a  display  tube  with  long  persistence.   Such  is  not  the  case 
for  color  since  there  is  no  color  tube  with  long  persistence  available. 

A  necessary  requirement  of  the  system  is  the  capability  of 
writing  into  the  memory  with  the  light  pen  in  order  to  write  and  draw 
boundaries  on  the  display.   Therefore,  the  memory  must  possess  a  local 
writing  capability.   It  is  also  desirable  that  local  erasure  be  available 
so  that  one  may  make  small  corrections  to  what  has  been  drawn  or  written 
on  the  display.   Also,  it  is  necessary  to  possess  the  capability  of 
totally  erasing  all  colors  and  all  outlines.   In  addition,  the  storage 
should  be  indefinite  so  that  the  display  may  be  viewed  for  long  periods 
of  time  without  noti cable  deterioration.  Finally,  the  memory  must 
possess  enough  capacity  to  allow  storage  of  the  required  information. 

For  a  resolution  of  500  lines  vertically  and  horizontally, 
250,000  elements  must  be  stored.   Since  there  are  three  primary  colors 
the  number  of  required  elements  increases  to  750,000.   The  fact  that 


-10- 

750,000  are  re  {uired  rather  than  500, 000  results  from  the  fact  that  tl 
three  primaries  yield  eight  possible  signals:  red,  blue,  grei 
yellow,  magenta,  white  and  black.   Thus,  although  two  bits  is  sufficient 
to  encode  the  individual  colors  red,  blue  and  green,  three  bits  are 
re  iuired  if  all  combinations  are  allowed.   Storage  of  the  outlines 
(boundaries)  in  addition  to  the  colors  results  in  a  total  of  10  stored 
elements.   If  shades  of  gray  are  desired  and  must  be  stored  digitally 
then  two  bits  are  required  for  each  color  for  four  shades  of  gray.   This 
requires  1.5  x  10  bits  for  the  colors,  0.25  x  10  more  for  the  outlines 
(assuming  no  shades  of  gray)  for  a  total  of  1.75  x  10  bits.   If  the 

shades  of  gray  can  be  stored  as  an  analog  signal  then  the  capacity  required 

6 
is  10  bits  (250K  for  each  color  and  the  outline).   Of  course,  at  any 

given  time  the  actual  capacity  being  used  would  normally  be  less  than  any 
of  these  figures.   However,  since  there  is  no  restriction  on  the  size  or 
shape  of  the  objects  written  on  the  display,  the  capability  for  storing 
these  capacities  must  be  present.   As  an  alternative  scheme  to  storing 
the  individual  picture  elements  one  could,  for  example,  consider  storing 
a  point  by  means  of  storing  the  address  of  the  point  on  the  display  in- 
stead of  the  point  itself.   For  a  500  x  500  display  this  requires  the 
storing  of  9  bits  for  the  X  address,  9  bits  for  the  Y  address  and  3  bits 
for  the  color  or  for  each  point,  a  total  of  21  bits.   Thus,  for  the  same 
memory  capacity  (750K)  only  1/7  (l^$)  as  many  points  can  be  stored.   This 
is  clearly  inadequate  for  large  colored  areas  which  can  easily  cover  80% 
of  the  screen.   In  addition,  it  would  be  impossible  to  maintain  a  reasonable 
regeneration  rate  if  each  point  had  to  be  decoded  and  converted  to  an 
analog  signal  in  order  to  generate  the  appropriate  deflection  for  dis- 
playing that  element.   Finally,  it  should  be  mentioned  that  500  elements 


-11- 

horizontally  results  in  a  capability  of  storing  250  line  pairs  (alter- 
nating "black  and  white  for  example) .   Thus  the  actual  number  of  lines 
resolution  (white  on  a  black  background  or  vice  versa)  for  500  elements 
is  250.   Also,  in  order  to  read  out  500  elements  in  a  standard  television 
format,  a  reading  rate  of  10  bits /sec  is  required.   (See  Section  k   for 
a  discussion  of  the  standard  television  format.) 

Various  types  of  storage  media  are  available  today  which  can 
be  considered  for  possible  use:   magnetic  tape,  magnetic  cores,  magnetic 
drum,  magnetic  disc,  direct  view  storage  tubes,  electrical  in  -  electrical 
out  storage  tubes  and  scan  conversion  tubes. 

Magnetic  tape  is  not  suitable  for  graphical  storage  because  of 
insufficient  reading  rate  and  the  unavailability  of  local  erase  capability. 
Although  commercial  color  recorders  are  available  (which  do  not  have  local 
erase  capability) ,  they  usually  utilize  NTSC  encoding  or  some  similar 
scheme.   Under  these  conditions  the  color  information  is  of  low  resolution. 
The  addition  of  local  erasure  to  this  type  of  system  is  difficult  since 
the  information  stored  on  the  tape  is  encoded.   Finally,  the  cost  of  these 
machines  is  quite  high. 

A  core  memory  could  be  used  if  the  required  capacity  could  be 
achieved  at  a  reasonable  cost.   In  order  to  read  out  of  such  a  device, 
500  bits  are  required  in  50  usee  or  one  6U  bit  word  every  6  usee.   This 
would  be  no  problem  for  some  memories  available.   However,  the  cost  of 
such  a  device  is  high  enough  to  make  it  impractical.   Added  to  the  cost 
of  the  core  memory,  of  course,  is  the  additional  circuitry  required  to 
convert  from  a  parallel  readout  to  the  serial  readout  as  required  by  the 
display. 

A  magnetic  drum  could  be  used.   In  order  to  achieve  the 
required  reading  rate,  however,  a  large  drum  would  be  required.   Again 


the  cost  of  such  a  device  is  high.  Nonetheless,  some  current  dispj 
systems  are  successfully  making  use  of  drums. 

It  is  also  possible  to  use  a  direct  view  electrostatic  st  . 
tube.   The  direct  view  tube  has  electrical  signal  input  and  a  visual 
display  for  output  by  means  of  a  viewing  screen.   This  type  tube  suffers 
from  the  disadvantage  that  in  order  to  achieve  electrical  readout,  it  is 
usually  necessary  to  view  the  tube  with  a  photo  sensitive  pick-up  device. 
This  type  of  memory  cell  was  investigated  in  the  ARTRIX  project  at  the 
University  of  Illinois  Digital  Computer  Laboratory.   In  addition  to  the 
difficulties  associated  with  obtaining  readout,  these  tubes  have  low 
resolution  for  long  persistence  and  short  persistences  for  high  resolution. 
Recently,  Tektronix  has  developed  a  tube  with  about  15  minutes  storage 
time  and  a  resolution  of  800  (TV)  lines  vertically  and  600  (TV)  lines 
horizontally.   The  tube  is  large,  however,  so  that  the  density  is  only 
about  95  (TV)  lines/inch.   The  writing  speed  of  this  tube  is  also  low.- 
Even  with  these  disadvantages,  this  tube  is  an  improvement  over  what  has 
been  available  in  the  direct  view  storage  tube  field.   Lack  of  local 
erasure  capability  is  another  disadvantage  of  these  tubes. 

Another  type  of  storage  tube  has  electrical  input  and  electrical 
output  and  is  frequently  used  for  scan  conversion.   The  problems  associ- 
ated with  these  tubes  are  short  storage  time  under  continuous  readout 
operation  and  beam  registration  problems  when  switching  tube  potentials 
in  order  to  go  from  a  writing  mode  of  operation  to  an  erasing  mode  of 
operation.   These  tubes  do  have  adequate  writing  speed  and  excellent 
resolution,  however. 

A  storage  tube  with  inverse  properties  would  be  very  useful  for 
coloring.   In  such  a  tube  the  storage  surface  would  be  conductive  until 
it  had  been  written  on  by  an  electron  beam  or  incoming  light.   In  an  area 


-13- 

where  it  had  been  written  it  would  then  become  insulating.   If  the  in- 
sulated area  is  the  boundary  of  the  region  to  be  colored,  then  a  small 
amount  of  charge  deposited  inside  the  region  initially  will  spread 
uniformly  over  the  interior  of  the  boundary.   Upon  scanning  the  tube, 
an  electrical  signal  will  be  produced  which  represents  the  area  which  was 
to  be  colored.   The  possibility  of  such  a  device  is  being  explored  at 
the  University  of  Illinois  Digital  Computer  Laboratory.   The  major  draw- 
back to  this  scheme  seems  to  be  finding  a  material  which  becomes  non- 
conducting rather  than  conducting  under  some  form  of  exitation.   It  may 
be  possible  to  use  the  usual  photoconductive  effect  in  conjunction  with 
a  black  trace  cathode  ray  tube  instead,  however. 

Finally,  the  magnetic  disc  is  a  possible  storage  media.   Until 
recently,  the  disc  did  not  possess  sufficient  storage  or  a  high  enough 
reading  rate.   However,  current  announced  devices  are  approaching  the 
necessary  rate  and  capacity  for  the  storage  of  pictorial  information. 
These  new  discs  are  manufactured  by  Data  Disc,  Inc.  of  Palo  Alto,  Cali- 
fornia.  Data  Disc  uses  a  proprietary  method  of  producing  their  discs 
along  with  in- contact  heads  to  achieve  digital  storage  of  10  bits /track 
and  bit  rates  of  3  x  10  bits/sec  for  a  12"  disc.   It  is  possible  to  get 
6k   tracks  on  a  disc  for  a  storage  capacity  of  6k   x  10  bits.   Specifi- 
cations claim  video  recording  frequencies  up  to  U.2MHz  and  recording  has 
been  done  up  to  5MHz.   Under  development  are  higher  capacity  disc  systems. 

•  A  comparison  of  possible  storage  media  is  shown  in  Table  1. 
As  indicated  by  the  table,  the  disc  possesses  local  write  and  erase,  total 
erase,  continuous  read  and  long-term  storage  capability.   In  addition, 
it  can  store  k   or  5  shades  of  gray.   For  these  reasons  the  disc  was 
chosen  as  the  memory  element  for  the  Tricolor  Cartograph.   Because  the 
capacity  for  the  disc  chosen  is  10  bits  with  a  bit  rate  of  3  x  10  ,  the 


COMPARISON  OF  MEMORIES  FOR  TRICOLOR  CARTOGRAPH 


-Ik- 


^\  STORAGE 
\MEDIA 

REQUIREMENT     \. 

< 

EH 

w 

o 
o 

o 

CO 
M 

n 

DIRECT  VIEW 
STORAGE  TUBE 

SCAN 
CONVERTER 

CONTINUOUS  READ 

X 

X 

X 

X 

X 

X? 

LOCAL  WRITE 

X 

X 

X 

X 

x 

X 

LOCAL  ERASE 

? 

X 

X 

X 

- 

9 

TOATL  ERASE 

X 

X 

X 

X 

X 

X 

INDEFINITE  STORAGE 

X 

X 

X 

X 

X 

- 

CAPACITY 

AND 

READ  RATE 

- 

X? 

X? 

X? 

- 

X 

COST 

H 

H 

H 

M 

M 

H 

GRAY  LEVEL  STORAGE 

X 

X? 

X? 

X 

- 

X 

H  =  HIGH 


M  -  MODERATE 


TABLE  1. 


-15- 

resolution  of  the  system  cannot  be  500  elements.  A  discussion  of  the 
characteristics  of  the  actual  system  will  be  found  in  Section  k. 

It  should  be  pointed  out  that  storage  units  with  insufficient 
reading  rates  can  be  used  by  multiplexing  several  channels  and  using  an 
intermediate  fast  storage  media.  Such  methods  were  considered  to  be  too 
complex  and  were  thus  not  considered.  What  was  desired  was  a  memory 
which  could  be  read  and  displayed  without  complex  interfacing. 

3-2  The  Processor 

The  major  problem  associated  with  the  processor  is  that  of 
detecting  the  boundaries  of  a  figure  such  that  their  location  is  determined 
in  some  meaningful  way.   If  one  assumes  that  the  format  of  the  pictorial 
data  can  take  any  form,  then  several  scanning  methods  seem  to  offer  promise 
as  a  means  of  boundary  detection.   These  are:   the  spiral  scan,  the  radial 
scan,  the  bounce  scan  and  the  lineal  scan  with  and  without  pen  or  boundary 
tracing.   In  addition,  a  boundary  enumeration  scheme  can  be  considered 
with  the  lineal  scan. 

For  the  spiral  scan,  the  scanning  of  the  boundary  is  done 
starting  at  a  point  indicated  by  the  light  pen  (and  known  to  be  inside 
the  boundary  of  interest)  and  spiraling  out  from  this  point  until  it 
intersects  a  boundary.   During  the  time  it  is  spiraling,  coloring  takes 
place.   One  disadvantage  of  this  method  is  that  the  only  figure  that 
could  be  colored  in  one  operation  is  a  circle.   A  scheme  could  be  imple- 
mented which  would  only  sense  the  boundary  (allowing  the  scan  to  continue) 
and  stop  the  coloring,  allowing  it  to  commence  again  after  again  sensing 
a  boundary.  With  this  scheme,  coloring  would  result  after  each  even 
number  of  intersections  with  a  boundary.   The  possible  occurrence  of 
adjacent  boundaries  and  cusps,  however,  eliminates  the  usefulness  of  this 

SO.hPTIlP  . 


-16- 

Use  of  a  radial  scan  is  also  possible  and  would  probably  yield 
somewhat  better  results  than  the  spiral  scan  for  most  figures.  For  the 
radial  scan,  scanning  again  begins  at  a  point  determined  by  the  light  ; 
and  radiates  from  it  while  slowly  moving  about  it  in  a  circular  manner. 
However,  it,  too,  could  not  cover  all  of  a  figure  in  one  operation  and  in 
addition,  it  suffers  from  non-uniformity  since  adjacent  scan  lines  diverge 
with  increasing  distance  from  their  starting  point. 

The  lineal  scan  consists  of  scanning  the  figure  with  parallel 
scans.   These  could  be  horizontal,  vertical  or  at  some  oblique  angle. 
With  this  method,  given  the  initial  point,  it  would  be  necessary  to  scan 
both  ahead  of  and  behind  this  point  (unless  it  was  on  the  boundary).   Again. 
it  would  not  be  possible  to  cover  all  of  some  figures  in  one  operation 
utilizing  a  single  scanning  direction.   If,  however,  two  orthogonal 
directions  can  be  used  it  is  possible  to  color  the  entire  figure.   In 
this  case,  however,  it  is  difficult  to  determine  when  to  cease  scanning  in 
one  direction  and  commence  scanning  in  the  other.   The  radial,  spiral,  and 
lineal  methods  are  illustrated  in  Figure  k. 

It  is  interesting  to  note  in  passing  that  when  a  human  colors 
a  bounded  area  with  a  pencil,  all  of  the  above  methods  are  put  in  use. 

These  three  scanning  methods  all  require  some  means  of  sensing 
when  the  boundary  has  been  reached.   This  means  that  when  the  scan  reaches 
a  boundary,  a  signal  must  be  produced  to  signify  this  fact.   If  such  a 
signal  could  be  generated,  it  would  be  possible  to  confine  the  scanning 
to  the  interior  of  the  boundary.   Under  these  conditions  the  bounce  scan 
could  be  used. 

The  bounce  scan  consists  of  scanning  in  a  given  direction  until 
a  boundary  is  encountered  at  which  time  the  scan  is  reversed  and  directed 
away  from  the  boundary  and  continues  until  the  entire  interior  has  been 


-17- 


A.  Spiral 


B.  Radia 


C.  Lineal 


Figure  h.      Scanning  Methods 


-1/ 

covered.   The  disadvantages  of  this  method  are  difficulties  in  imple- 
mentation of  such  a  scanning  system  and  the  problem  associated  with  sensing 
when  the  coloring  operation  is  complete.   In  order  to  sense  when  the  oper- 
ation is  complete,  it  is  necessary  that  some  control  be  exercised  over 
the  directions  of  the  various  bounces  of  the  scan.   In  other  words,  some 
systematic  method  of  bouncing  would  be  required. 

If  one  is  willing  to  impose  more  restrictions  on  the  operator, 
other  scanning  methods  can  be  used.   Thus,  if  the  operator  is  required  to 
move  the  pen  from  the  upper  extremity  of  the  figure  to  the  lower  extremity 
of  the  figure  (remaining  inside  the  boundary)  and  a  lineal  scan  is  used, 
coloring  can  be  done  line  by  line  as  the  pen  is  moved  across  the  figure. 
If  a  television  like  scan  is  used,  it  is  a  simple  matter  to  color  all 
lines  starting  at  the  pen  and  stopping  at  the  next  boundary.   Coloring 
between  the  boundary  prior  to  the  pen  and  the  pen  itself  is  not  simple 
since  the  boundary  has  already  been  passed  when  the  location  of  the  pen 
is  sensed.   This  area  would  have  to  be  colored  on  a  succeeding  pass,  which 
for  a  television  type  scan  is  too  much  later  to  be  practical. 

This  latter  difficulty  can  be  circumvented  by  requiring  the 
operator  to  pass  the  pen  either  along  the  boundary  or  just  ahead  of  it 
(with  respect  to  the  scan).   Under  these  circumstances,  the  coloring  can 
be  done  between  the  next  two  boundary  points.   Of  course,  this  method 
would  still  not  completely  color  some  figures.   In  addition,  the  coloring 
would  most  certainly  be  erroneous  if  the  operator  happened  to  go  above 
the  upper  extremity  of  the  figures  or  below  the  lower  extremity  since  in 
that  case  the  next  two  boundaries  (if  they  exist)  would  not  be  part  of  the 
one  which  was  being  used.   These  three  methods  of  boundary  and  pen  tracing 
are  shown  in  Figure  5- 


■19- 


A.  Bounce  Scan 


B.  Interior   Pen   Tracing 


C.  Exterior  Pen  Tracing 


Figure  5.   Boundary  and  Pen  Tracing 


-20- 

No  matter  what  scanning  methoc.  is  used  there  are  certain 
boundary  configurations  which  can  cause  problems.   The      figurations 
consist  of  the  cases  in  which  the  boundary  either  becomes  tangent  to  the 
scan  or  divides  into  two  or  more  boundaries.   Some  cases  for  which  this 
occurs  are  the  cusp,  the  lobe  and  the  branch  as  shown  in  Figure  6.   The 
cusp  and  lobe  could  cause  difficulties  insofaras  they  appear  as  only  one 
point  when  the  scan  is  tangent  to  their  tip.   This  same  problem  exists 
for  a  boundary  which  is  parallel  to  the  scan.   The  existence  of  these 
boundary  configurations  rules  out  coloring  schemes  which  rely  on  the 
enumeration  of  boundary  points  since  when  these  configurations  occur  they 
appear  as  one,  two,  three  or  even  more  points. 

In  view  of  the  foregoing  discussion,  it  is  clear  that  the  basic 
problem  associated  with  the  scanning  of  the  figure  is  determining  when 
the  scan  is  inside  and  when  it  is  outside  the  boundary  of  interest.   In 
addition,  it  cannot  be  just  any  boundary  but  the  boundary.   Information 
on  the  boundary  is  available  regularly  in  the  process  of  generating  the 
display.   However,  since  the  disc  has  been  shown  to  be  the  only  storage 
media  which  is  both  suitable  and  available,  its  use  fixes  the  format  of 
the  data.   This  format  is  serial  so  that  information  about  the  boundary 
is  available  only  periodically.   Unless  the  boundary  information  is  re- 
written in  another  form,  it  will  be  necessary  to  synchronize  the  scanning 
of  the  boundary  with  the  periodically  appearing  boundary  information.   Of 
course,  by  utilizing  a  scan  converter  the  disc  output  may  be  transformed 
into  any  other  type  of  format.   This  is  also  accomplished  if  the  serial 
disc  information  is  scanned  in  a  non-lineal  manner  by  sampling  the  disc 
output  appropriately.   This  results  in  a  very  low  effective  scanning  rate, 
however.   By  utilizing  a  scan  converter  the  spiral,  radial  or  lineal 
scanning  method  may  be  employed.   The  cost  of  a  scan  converter  is  such  as 


-21- 


A.   Cusp 


B.  Lobe 


C.  Branch 

Figure  6.      Problem  Boundaries 


-22- 

to  rule  out  its  use  in  a  project  the  size  of  the  Tricolor  Cartograph. 
Besides  cost  there  are  operational  problems  such  as :   the  time  required 
to  read  and  write  between  the  scan  converter  and  the  disc,  the  difficulty 
of  erasing  locally  with  good  registration,  the  problems  associated  with 
attempting  to  write  (in  order  to  do  the  coloring)  and  read  (in  order  to 
sense  the  boundaries)  simultaneously  and  the  fact  that  it  is  difficult  to 
prevent  the  transfer  of  the  outline  back  into  the  color  memory  after  the 
coloring  operation  is  complete. 

Clearly,  it  would  be  desirable  if  the  disc  output  could  be 
used  directly.   As  a  result,  a  lineal  scan  which  runs  synchronously  with 
the  disc  is  used  in  the  Tricolor  Cartograph.   This  means  that  the  boundary 
information  from  the  disc  occurs,  in  time,  when  the  scan  reaches  the 
boundary.   In  order  to  store  positional  information  in  the  system,  two 
counters  are  used.   The  horizontal  counter  digitizes  each  horizontal 
scanning  line  into  9  bits.   The  vertical  counter  counts  the  number  of 
scanning  lines.   Thus,  the  horizontal  count  is  an  indication  of  position 
on  a  given  scanning  line  and  the  vertical  count  determines  which  scanning 
line.   These  two  counters  allow  the  digital  storage  of  coordinates  in  the 
form  of  a  9  bit  horizontal  and  a  9  bit  vertical  binary  representation. 
During  the  coloring  operation,  the  required  initial  point  is  determined 
by  the  placement  of  the  light  pen  when  the  operator  indicates  some  point 
within  the  interior  of  the  chosen  boundary.   The  coordinates  of  this  pen 
location  are  stored  at  this  time  and  used  as  a  reference  point  during  sub- 
sequent operations.   While  coloring,  there  are  two  boundary  points  of 
interest  on  each  horizontal  scanning  line.   These  are  defined  to  be  the 
last  boundary  point  preceding  the  horizontal  pen  position  and  the  first 
boundary  point  following  the  horizontal  pen  position.   The  horizontal  pen 
position  referred  to  is  that  position  which  was  stored  initially  when  the 


-23- 

operator  designated  an  interior  point.   In  order  to  color  all  of  some 
figures  with  this  scheme,  more  than  one  pen  placement  will  be  required. 
Since  the  boundary  point  preceeding  the  pen  position  is  not  sensed  until 
after  the  pen  position  has  been  passed,  it  is  then  too  late  to  color  on 
that  scan.   In  order  to  color  the  proper  line,  a  wait  of  an  entire  frame 
would  be  required.   To  avoid  this,  the  coloring  is  delayed  just  one  line. 
This  means  that  there  will  be  a  misregistration  of  two  lines  for  the  coloring 
(the  system  is  interlaced).   Since  most  figures  have  boundaries  which  are 
slowly  varying,  this  misregistration  should  not  be  noticable.   A  complete 
description  of  the  method  used  is  contained  in  Sections  k   and  5« 

3.3  The  Display 

Although  various  methods  of  displaying  color  information  are  in 
use  currently,  only  some  type  of  color  cathode  ray  tube  is  both  suitable 
for  a  small  console  and  available  at  a  reasonable  cost.   Of  the  color 
tubes  which  have  been  proposed  only  the  familiar  tricolor  tube  is  in  wide- 
spread usage.   Thus,  the  display  unit  of  the  Tricolor  Cartograph  utilizes 
a  three  color  television  monitor  having  a  tricolor  tube  as  its  display 
element.   Since  these  monitors  are  designed  for  standard  525  line  television 
they  are  directly  compatible  with  the  disc  memory  which  is  also  designed 
to  operate  at  standard  television  rates. 


k.        DESCRIPTION  OF  S/STEM 

Before  embarking  on  a  description  of  the  operation  of  the  Tri- 
color Cartograph,  a  brief  review  of  standard  television  concepts  will  be 
given. 

4.1  A  Brief  Review  of  Television  Concepts  and  Nomenclature 

Standard  television  consists  of  a  525  line  scanning  format. 
When  facing  a  monitor,  the  lines  are  scanned  from  left  to  right  hori- 
zontally and  from  top  to  bottom  vertically.  Horizontal  scanning  is  at  a 
rate  of  15,750  lines  per  second.   At  this  rate,  the  entire  525  lines  is 
scanned  in  1/30  sec.   This  is  called  one  frame.   Each  frame  is  divided 
into  two  interlaced  fields  each  requiring  1/60  second.   The  interlacing 
is  accomplished  by  starting  the  vertical  retrace  of  the  scanning  beam  at 
an  appropriate  time  (either  at  the  end  of  horizontal  scan  or  halfway 
through  it).   This  interlacing  then  places  the  lines  of  one  field  halfway 
between  those  of  the  others. 

The  two  fields  are  designated  even  and  odd.   On  the  basis  of 
the  above  rates,  the  duration  of  one  line  is  about  63-5  usee,  one  frame 
33-3  msec,  and  one  field  16.7  msec.   It  is  important  to  note  that  neither 
the  entire  525  lines  nor  the  entirety  of  any  one  line  is  usable  for 
pictorial  information.   This  results  from  the  fact  that  time  is  required 
for  retrace  of  the  scanning  beams.   Thus,  between  20  and  30  lines  are 
lost  (assume  25)  leaving  about  500  lines  and  about  16%   of  each  line  is 
lost  (~10  (i  sec.)  giving  a  useable  line  of  about  53  u-sec.  duration. 

The  scanned  area  is  k/3   as  wide  as  it  is  high.   This  is  called 
the  aspect  ratio.   The  bandwidth  required  for  a  given  resolution  can 
easily  be  determined.   The  relationship  in  the  horizontal  case  is: 


-25- 


BW=Vt 


2K..T. 


*H 


where  R  =  number  of  half  cycles  per  line  [R^/2  =  #  of  cycles /line] 
N  =  number  of  lines  per  frame 
fC  =  %   of  line  actually  used  (~Qh%) 
T  =  period  of  frame  (1/30  sec.) 

The  1/2  results  from  the  fact  that  the  television  industry 
counts  each  cycle  as  two  lines  resolution,  not  one.   Thus  the  resolution 
given  by  R^   is  twice  the  actual  resolution.   The  above  gives  R^  =  107  lines 
per  MHz  bandwidth. 

The  vertical  resolution  is  given  by: 

*v  =  W. 

"where  N  =  actual  number  of  scanning  lines  (~500) 
a 

K^  bs  the  Kel  factor  (-.7) 

K.  =  1  if  a  full  interlace  is  used  and  0.75  if  a  random  interlace 
1  ' 

is  used. 
The  Kel  factor  is  a  statistical  correction  which  takes  into 
account  the  fact  that  it  is  not  possible  to  transmit  any  information 
corresponding  to  the  part  of  the  picture  which  falls  between  the  scanning 
lines.   They  are  not  "seen"  by  the  camera.   Recently,  some  experimentation 
was  done  in  which  this  factor  was  "effectively"  increased  by  purposely 
causing  the  raster  to  move  up  and  down  over  a  period  of  frames.   [of  course 
for  any  one  frame  the  factor  is  still  the  same.]   In  this  way  information 
missed  in  one  scan  can  sometimes  be  detected  during  the  next.  R^  is 
about  350  for  standard  television.   It  is  interesting  to  note  that  for 
commerical  black  and  white  television  R^  =  350  and  R^  =  350  (the  bandwidth 


-26- 

is  3-3-5MHz).   For  color  television  the  color  information  bandwidth  is 
0.5MHz  giving  a  resolution  of  about  h-0   lines  for  the  color  information. 

In  a  television  system  the  required  timing  pulses  are  usually 
obtained  from  a  crystal  oscillator.   The  basic  pulses  used  to  control  a 
television  system  are  derived  from  this  oscillator  and  are  known  as 
horizontal  and  vertical  drive  (HD  and  VD),  horizontal  and  vertical  syn- 
chronization (HS  and  VS)  and  horizontal  and  vertical  blanking  (HB  and 
VB) .   The  drive  pulses  are  used  to  initiate  the  horizontal  and  vertical 
scans  in  the  camera  or  camera  systems.   They  are  the  basic  timing  pulses 
used  in  all  video  processing.   The  synchronization  pulses  and  blanking 
pulses  are  added  to  the  outgoing  video0  The  synchronization  pulses  are 
used  to  synchronize  a  receiver  and  the  blanking  pulses  are  used  to  blank 
out  its  scanning  beam  during  retrace. 

The  vertical  drive  pulse  is  about  0-7  msec,  in  duration  and  the 
horizontal  drive  pulse  about  6.35  (i  sec.   The  sync  and  blanking  pulses 
are  wider.   The  drive  pulses  are  the  basic  timing  pulses  used  in  the 
Tricolor  Cartograph. 

In  order  to  handle  color  information  in  a  television  system, 
either  three  separate  video  signals  (red,  blue  and  green)  must  be  processed 
or  the  three  signals  must  be  encoded  and  processed  as  a  unit.   In  the 
Tricolor  Cartograph,  three  separate  channels  are  used. 

h. 2     Physical  Description 

The  Tricolor  Cartograph  is  shown  in  Figure  7-   It  consists  of 
a  display  console  and  a  control  console.   The  display  console  contains 
the  light  pen,  the  control  switches  and  the  color  display.   The  control 
console  contains  the  power  supplies,  the  processor  and  the  memory.   The 
color  display  is  a  Model  CYM  21  Color  Television  Monitor  manufactured  by 


-27- 


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-2f 

Conrac  Division  of  Giannini  Controls  Corporation  of  Glendora,  California. 
The  memory  is  a  Model  ^-04  Video  Memory  manufactured  by  Colorado  Video, 
Inc.,  Boulder,  Colorado.   The  entire  system  utilizes  a  standard  525  line 
television  format,  as  previously  described. 

Figure  8  shows  a  block  diagram  of  the  system.   Power  for  the 
entire  system  is  obtained  through  the  circuit  breaker  panel.  D.C.  power 
is  supplied  by  the  two  modular  power  supply  units  which  produced  -5,  +10, 
+25  volts.   The  power  is  distributed  by  the  Main  Junction  Box.   Control 
signals  pass  through  the  Display  Junction  Box  to  the  Main  Junction  Box 
and  on  to  the  Control  (Processor).   Video  signals  for  the  monitor  eminate 
from  the  Control.  All  signals  to  and  from  the  video  memory  originate  or 
terminate  at  the  Control.   The  Light  Pen  signal  passes  through  the  Dis- 
play Junction  Box  and  on  to  the  Control. 

k.3     The  Light  Pen 

The  Light  Pen  performs  two  functions.   First,  it  produces  a  • 
signal  designated  Enable  which  performs  logical  functions  in 'the  Control. 
These  functions  will  be  described  later.   Second,  it  produces  an  output 
pulse  in  response  to  light  input  from  the  phosphor  emission  of  the  Display. 

The  light  produced  by  the  phosphor  is  detected  by  a  photodiode. 
The  signal  thus  produced  is  amplified  by  a  two  stage  high  pass  preamplifier 
in  the  Light  Pen.   The  signal  then  passes  to  a  thresholding  amplifier. 
This  is  a  two  stage  high  pass  amplifier  whose  input  threshold  can  be  con- 
trolled so  as  to  produce  some  noise  immunity.   This  is  necessary  because 
of  the  extreme  sensitivity  of  the  light  pen  circuitry  in  conjunction  with 
the  fact  that  the  television  monitor  radiates  a  prominent  signal  at 
15,750  Hz  from  its  flyback  circuitry.   There  is  sufficient  coupling  of 
this  signal  to  the  pen  to  cause  spurious  pulses. 


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Figure  8.   Tricolor  Cartograph  Block  Diagram 


Since  the  pen  is  activated  by  the  detection  of  light  from  the 
raster,  it  is  necessary  to  display  a  raster  at  all  times  so  that  the  pen 
will  operate.   There  is  sufficient  gain  in  the  system  to  allow  the  back- 
ground level  to  be  quite  low.  However,  this  level  must  be  high  enough  to 
provide  an  adequate  signal  to  noise  ratio  for  proper  operation  of  the 
pen  circuits. 

After  this  thresholding  and  amplification  (in  the  Display  Junction 
Box)  the  pen  pulse  passes  to  a  pen  pulse  shaping  circuit  at  the  Processor. 
Here  the  pen  pulse  is  shaped  into  a  one  volt  pulse  120  nsec.  in  width. 
This  pulse  then  passes  to  three  3-input  video  adders  so  as  to  be  displayed 
as  a  marker  on  the  display.   It  also  passes  to  the  video  to  logic  con- 
verter where  it  is  converted  to  logic  levels  and  subsequently  used  in  all 
pen  operations  in  the  Processor. 

h.k     The  Display 

The  Display  is  a  red,  blue,  green  color  monitor  utilizing  a  21 
inch  tricolor  tube.   These  tubes  use  three  phosphor  grouped  in  triads 
across  the  face  of  the  tube.   The  three  phosphors  are  a  red  emitting,  a 
green  emitting  and  a  blue  emitting.   The  time  required  for  these  phos- 
phors to  decay  to  10$  of  their  initial  value  is  22  msec,  for  blue,  60 
msec,  for  green  and  1  msec,  for  red.   The  relative  emitted  energy  is 
highest  in  the  red  but  the  red  emission  is  in  very  narrow  spectral  bands 
whereas  the  green,  and  blue  energy  is  distributed  more  uniformly.   This 
results  in  the  total  integrated  energy  being  largest  in  the  green  followed 
by  the  blue  and  the  red.   This  results  in  a  very  low  sensitivity  of  the 
Light  Pen  to  the  red  phosphor.   The  pen  is  most  sensitive  to  green.   This 
is  so  even  though  the  intrinsic  sensitivity  of  the  photo-diode  is  much 
higher  in  the  red  than  in  the  green  or  blue. 


-31- 

The  triads  of  phosphor  are  spaced  at  intervals  of  0.029  inches. 
With  screen  dimensions  of  16  x  19  l/*+  the  possible  resolution  is  about 
550  dots  vertically  and  650  dots  horizontally.   The  electrical  resolution 
is  7MHz  or  750  lines  (i.e.  375  cycles). 

One  property  of  the  shadow  mask  tube  is  that  of  very  low  bright- 
ness.  This  results  from  the  fact  that  the  faceplate  transmission  is  only 
39%  and  more  important,  the  shadow  mask  transmission  is  only  15%-      Because 
of  this,  a  fairly  low  room  illumination  is  needed  when  viewing  the  Tri- 
color Cartograph. 

Four  signals  drive  the  color  monitor:   red,  green  and  blue 
video  and  sync.   The  sync  signal  is  generated  at  the  disc  memory.   The 
three  video  signals  all  originate  at  the  Processor. 

4.5  The  Memory 

The  Memory  utilizes  a  magnetic  disc  12  inches  in  diameter  driven 
by  a  hysteresis -synchromous  motor  at  1800  rpm.   There  are  5  channels:  h 
video  and  one  sync.  The  sync  track  is  used  to  generate  horizontal  and 
vertical  drive,  horizontal  and  vertical  sync,  and  blanking.   The  four  video 
tracks  are  used  for  red  video,  blue  video,  green  video  and  outline  video. 
The  outline  track  contains  all  the  boundary  information  for  the  figures. 
Each  of  these  k   video  tracks  has  two  inputs  and  one  output.   The  inputs 
are  write  and  erase  and  the  output  is  read.   There  is  one  additional  in- 
put to  the  Memory:   chop.   The  chop  input  controls  an  internal  chopper 
which  can  be  used  when  writing. 

There  are  two  different  methods  of  writing  on  the  disc:   direct 
and  chopped.   In  direct  writing,  incoming  pulses  are  written  directly  on 
the  disc.   Pulses  of  100  ns  width  are  written  in  this  mode  giving  about 


-32- 

5MHz  response  or  about  500  line  resolution.   In  the  chop  mode,  the  in- 
coming signal  is  chopped  by  the  internal  chopper.   Chopping  is  required 
when  it  is  desired  to  write  wide  pulses  onto  the  disc  as  is  required  in 
the  coloring  of  a  large  area.   This  is  necessitated  by  the  fact  that  the 
read  mechanism  is  by  means  of  detecting  a  changing  megnetic  flux  on  the 
disc.   Thus,  if  the  flux  is  not  continually  changing  there  is  no  output. 
In  the  Tricolor  Cartograph  the  chopper  period  is  about  350  nsec.  corres- 
ponding to  2.9MHz.   This  is  quite  close  to  limit  specified  for  the  disc 
(100,000  points  or  3MHz ) .   At  frequencies  above  this,  the  output  de- 
creases rapidly.   A  350  nsec.  period  yields  15^-  cycles  per  line  or  about 
300  line  resolution.   In  addition,  the  chopper  is  arranged  to  produce  a 
dot  interlace  pattern.   This  is  accomplished  by  using  opposite  phases  of 
the  chopper  during  alternate  fields.   This  requires  that  the  chopper  start 
each  horizontal  line  in  the  same  phase  during  any  one  field.  Although  the 
chopper  is  quite  stable,  variations  in  the  drive  pulse  frequency  due  to 
sync  track  variations  make  it  difficult  to  maintain  the  dot  interlace  • 
pattern  over  an  entire  frame.   A  shift  of  only  175  nsec.  is  sufficent  to 
completely  reverse  the  phase  of  the  chopper  with  respect  to  an  adjacnet 
line  (which  occurs  l6rns  later  in  time).   This  is  a  0.001%  variation.   Of 
course  a  shift  of  any  multiple  of  the  period  results  in  restoration  of  the 
proper  phase  at  that  point.   The  result  of  this  is  to  produce  a  "beat" 
frequency  pattern  on  the  screen.   In  the  present  system,  this  non  uniformity 
of  the  dot  pattern  is  not  of  great  consequence  since  it  is  reasonably  stable 
over  a  period  of  a  few  minutes  which  is  all  that  is  required  for  coloring. 

For  a  system  requiring  long  term  stability,  both  of  the  above 
problems  can  be  eliminated  by  recording  a  chop  track  on  the  disc. 


-33- 

k.6     The  Processor 

The  Processor  consists  of  a  three  card-rack  unit  containing  all 
the  control  logic  and  video  processing  circuitry.   The  logic  is  performed 
with  Texas  Instruments  Series  7^N  transistor-transistor  logic  elements. 
The  video  circuitry  is  composed  of  discrete  components.   The  various  op- 
erations controlled  by  the  Processor  are:   the  total  erase  mode,  the  k 
pen  modes  and  the  coloring  mode.   These  will  be  discussed  briefly  in  the 
following  sections.  Detailed  circuit  and  logic  descriptions  will  be  found 
in  the  Appendix.  For  all  modes  the  color  or  colors  on  which  a  given  oper- 
ation is  to  be  performed  is  determined  by  three  color  selector  buttons .  One 
may  select  red,  green,  blue  or  any  combination  of  these.   (7  combinations) 

k.6.1     The  Total  Erase  Operation 

There  are  two  erase  operations:   Color  Erase  and  Outline  Erase. 
In  the  Color  Erase  operation  when  the  Color  Erase  button  is  depressed, 
an  erase  signal  is  applied  to  the  disc  tracks  corresponding  to  the  chosen 
color (s)  for  a  duration  of  one  frame. 

For  the  Outline  Erase  operation,  the  erase  signal  is  applied  to 
the  outline  track  for  one  frame. 

These  operations  result  in  the  disc  surface  at  the  track  in 
question  being  magnitized  in  one  direction  for  the  entire  frame.   This 
causes  all  previously  stored  information  to  be  removed. 

k.6.2     The  Pen  Modes 

There  are  five  pen  modes:   Color  Erase,  Outline  Erase,  Color 
Write,  Outline  Write  and  Color.   The  latter  is  explained  in  Section  k.6.3. 

In  the  Color  Erase  mode,  the  pulse  generated  by  the  pen  is  used 
to  drive  the  disc  erase  inputs  for  the  colors  chosen.   This  results 


•3k- 

in  the  erasure  of  points  from  the  corresponding  disc  tracks. 

In  the  Outline  Erase  mode  the  pen  performs  a  similar  operation 

on  the  outline  track. 

In  the  Color  Write  mode  the  pulse  generated  by  the  pen  is  used 
to  drive  the  disc  write  inputs  for  the  chosen  colors.   This  results  in 
points  being  written  on  the  tracks  corresponding  to  those  colors . 

Similarly,  in  the  Outline  Write  mode  the  pen  writes  points  on- 
to the  outline  track  of  the  disc. 

In  all  of  the  above  modes  the  pen  can  be  used  to  do  free  hand 
writing  and  erasing  on  the  color  display.   The  Outline  Write  mode  is 
used  to  draw  the  outline  of  shapes  which  are  to  be  colored.   In  the 
Processor  the  video  from  the  outline  memory  is  added  equally  to  all  three 
of  the  color  video  signals,  red,  blue  and  green.   Thus  on  the  display  the 
outline  appears  white.   Before  the  outline  video  is  added  to  the  red, 
green  and  blue  video  signals,  it  is  delayed  in  order  to  compensate  for 
delays  which  occur  in  the  coloring  operation.   If  this  is  not  done,  the 
colored  areas  are  misregistered  slightly  from  the  outline. 

h.6.3     The  Coloring  Process 

As  mentioned  previously,  the  method  used  in  accomplishing  the 
coloring  of  closed  areas  is  a  compromise  between  the  various  conflicting 
requirements  imposed  on  the  system.   First,  there  are  no  shades  of  gray 
in  the  present  system.   The  introduction  of  shades  of  gray  into  the  system 
allows  a  much  wider  choice  of  colors  to  be  displayed.   However,  since  it 
is  an  operator  choice,  the  large  number  of  possibilities  would  necessitate 
some  sort  of  preview  method  which  would  allow  the  operator  to  adjust  for 
the  saturation  of  his  choice  and  then  store  it.   The  disc  memory  used 
allows  only  a  limited  gray  scale  and  would  thus  limit  the  usefulness  of 


-35- 

this  capability.   In  addition,  this  feature  is  just  an  extension  of  the 
present  system  and  does  not  change  it  in  principle.' 

Second,  the  coloring  as  accomplished  in  the  Tricolor  Cartograph 
results  in  a  misregistration  of  the  color  information  by  two  television 
lines  vertically. 

The  coloring  method  used  is  best  described  in  reference  to 
Figures  9  and  10.   Initially  the  pen  is  pointed  to  some  interior  point 
like  X  in  Figure  9  and  the  enable  button  is  depressed.   When  the  pen 
pulse  is  received  by  the  processor,  it  begins  a  search  for  the  bottom 
point,  B,  and  the  top  point,  T.   These  points  correspond  to  the  points  on 
the  outline  whose  horizontal  location  is  the  same  as  the  horizontal  pen 
location.   The  processor  stores  the  location  of  the  closest  points  above 
and  below  the  initial  pen  location  which  satisfy  the  above  conditions. 
In  other  words,  it  determines  the  nearest  points  of  intersection  of  the 
outline  with  a  line  drawn  vertically  through  the  original  pen  point. 
Having  determined  these  points  the  processor  uses  them  as  the  vertical 
extremities  of  the  area  that  will  be  colored  during  the  current  operation. 
It  is  now  necessary  to  determine  the  horizontal  extremities.   This  is 
done  as  the  lines  are  being  scanned.  During  any  one  line,  the  processor 
simultaneously  performs  two  operations.  First,  it  determines  the  last 
boundary  point  prior  to  the  pen  locations  and  the  first  point  after  the 
pen  location.   Second,  it  colors  between  similar  points  which  were  deter- 
mined on  the  previous  line.   This  is  shown  in  Figure  10.   Thus,  there  is 
a  misregistration  of  two  lines.   Because  the  lines  are  very  close  together, 
this  does  not  produce  any  deterioration  in  the  quality  of  the  picture 
while  at  the  same  time  it  allows  the  completion  of  an  entire  coloring  op- 
eration in  about  two  frames  (1/15  second) . 


-36- 


X  =  Pen  Location 
T  =Top  Point 
B  =  Bottom  Point 


Figure  9.   Top  and  Bottom  Point  Location 


-37- 


A  =  Points  used  to  color  the  line  given  by  o 


Figure  10.   Left  and  Right  Point  Location 


-38- 

Note  that  for  a  multiply  connected  region  as  shown  in  Figure  > 
and  10,  no  coloring  is  done  on  the  side  of  an  interior  area  away  from  the 
pen  point.   Also,  for  some  figures  such  as  the  one  shown,  it  is  necessary 
to  move  the  pen  to  several  locations  in  order  to  completely  color  the 
entire  interior.   Thus,  to  color  the  figure  shown  in  Figure  9j  "the  pen 
would  have  to  be  moved  as  shown  in  Figure  11.  For  the  method  used,  the 
worst  case  is  a  narrow  boundary  which  is  at  45  to  the  scan. 

During  the  frame  in  which  the  coloring  is  done,  the  processor 
starts  at  the  pen  location  and  colors  the  lower  half  of  the  figure  during 
the  first  field.   It  then  colors  all  of  the  figure  during  the  next  field. 
Finally  it  colors  the  top  of  the  first  field  and  stops  when  it  reaches 
the  pen  position  again. 

The  sequential  operations  of  the  processor  during  the  coloring 
operation  are  shown  in  Figure  12.   The  cycle  is  initiated  by  the  pen 
pulse  at  1.   The  pen  pulse  corresponds  to  the  output  of  the  light  sen- 
sitive pen  and  occurs,  in  time  and  space,  somewhere  inside  of  the  closed 
boundary  whose  interior  is  to  be  colored.   With  the  occurance  of  this 
pulse,  the  horizontal  and  vertical  pen  coordinates  are  stored  in  the  hori- 
zontal and  vertical  pen  position  registers.   At  the  same  time,  subsequent 
pen  pulses  are  locked  out  for  the  next  seven  fields  or  until  a  coloring 
operation  is  complete  at  which  time  a  new  cycle  can  be  inititated.   These 
operations  are  indicated  at  2  in  Figure  12.   The  counter  which  counts  out 
the  seven  fields  is  shown  at  3«   This  counter  terminates  the  process  if 
no  top  and  bottom  point  are  found  within  the  7  fields  allowed.   When  both 
a  top  and  bottom  point  are  found,  this  counter  stops.   At  h   the  search 
for  the  bottom  points  begins.   This  is  done  by  finding  the  first  coin- 
cidence between  the  outline  and  the  horizontal  pen  position  which  was 
stored  previously.   This  search  is  indicated  at  5  and  occurs  when  no 
bottom  point  has  been  found.   At  6,  the  vertical  drive  pulse  occurs 


-39- 


Figure  11.   Coloring  the  Entire  Figure 


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-40- 


Figure  12.   Timing  Diagram  for  Coloring  Operation 


-lH- 
signifying  the  end  of  a  field.   This  signal  indicates  the  beginning  of  the 
top  point  search  and  the  end  of  the  bottom  point  search.   (Again  assuming 
that  no  top  point  has  been  found  on  a  previous  search.)   The  top  point 
search  is  shown  at  8.  For  the  top  point,  all  successive  coincidences 
between  the  outline  and  the  horizontal  pen  position  are  accepted,  each 
one  taking  precedence  of  the  previous  one.   This  process  terminates  at  9> 
8-bit  vertical  pen  coincidence,  with  the  last  top  point  prior  to  the 
vertical  pen  coincidence  being  retained.   The  pen  coincidences  referred 
to  are  obtained  from  a  coincidence  circuit  which  produces  an  output  pulse 
each  time  the  horizontal  and  vertical  counters  contain  the  same  count  as 
that  previously  stored  when  the  pen  pulse  occurred.   Thus,  at  10,  assuming 
that  both  the  top  and  bottom  points  have  been  found,  the  top  point  register 
contains  a  count  corresponding  to  the  TV  line  on  which  the  outline  last 
had  a  coincidence  with  the  horizontal  pen  position  prior  to  the  vertical 
pen  coincidence.   Similarly,  the  bottom  point  register  contains  a  count 
corresponding  to  the  first  line  after  the  vertical  pen  coincidence  on 
which  the  outline  had  a  coincidence  with  the  horizontal  pen  position.   If 
both  the  top  and  bottom  point  have  not  been  found  the  process  repeats 
starting  at  h.      Assuming  that  both  a  top  and  a  bottom  point  have  been 
found  during  seven  or  fewer  fields,  the  process  continues  at  11.   There 
are  two  different  vertical  pen  coincidences  used  in  the  system:   an  8  bit 
vertical  pen  coincidence  and  a  9  bit  vertical  pen  coincidence.   The  8 
bit  coincidence  occurs  every  field  whereas  the  9  bit  coincidence  occurs 
every  frame.   At  11  the  system  waits  for  a  9  bit  vertical  coincidence 
before  beginning  the  coloring.   This  is  done  only  as  a  convenient  means 
of  reference  for  performing  one  frame  of  coloring.   Thus 


-42- 

from  point  k   to  point  11  a  possible  n  fields  has  occurred  (n  <  7).   Note 
that  the  system  accepts  a  top  and  bottom  point  from  either  field.   At  12 
the  coloring  begins.   13  and  Ik   represent  the  operation  of  finding  the 
left  point  and  right  point  between  which  the  coloring  is  to  be  done.   Since 
there  is  a  one  line  delay  between  finding  these  points  and  using  them,  no 
coloring  is  done  on  the  first  line  and  the  choice  at  15  on  the  first  pass 
is  "no."  After  this,  horizontal  drive  occurs  at  18  signifying  the  end  of 
a  line.   Should  the  next  line  happen  to  be  the  line  containing  the  bottom 
point,  the  system  awaits  vertical  drive  before  coloring  the  top  half  of 
the  picture.   Assuming,  however,  that  the  bottom  point  has  not  been  reached, 
the  loop  returns  to  12  and  proceeds  through  15,  16,  and  17  using  the 
points  previously  found  at  13  and  Ik.      Of  course  there  is  no  delay  on 
passes  other  than  the  first.   The  left  point  and  right  point  are  deter- 
mined in  a  manner  similar  to  that  used  in  determining  the  top  point  and 
bottom  point.   For  the  left  point,  the  system  accepts  all  outline  points 
beginning  at  the  left  end  of  the  line  and  retains  the  last  one  when  the 
horizontal  pen  coincidence  occurs.   For  the  right  point,  the  system  retains 
the  first  outline  point  occurring  after  the  horizontal  pen  coincidence. 
At  point  20  then,  the  bottom  of  one  field  has  been  colored.   Just  as  there 
is  a  one  line  delay  in  starting  the  coloring,  the  coloring  stops  one  line 
prior  to  the  bottom  point.   Thus  the  coloring  is  actually  done  inside  of 
the  outline.   After  vertical  drive  at  20,  a  process  similar  to  that  for 
the  bottom  of  the.  figure  is  carried  out  for  the  top  of  the  figure.   The 
major  difference  is  that  the  test  at  29  is  for  8  bit  vertical  coincidence. 
When  an  8  bit  vertical  coincidence  is  obtained,  a  check  is  performed  at 
30  for  a  9  bit  coincidence.   On  the  first  field  there  will  be  none  and 
the  loop  returns  to  12  where  it  colors  the  other  field  for  the  bottom  of 
the  figure.   Then  at  19,  20  and  21  the  coloring  of  the  other  field  for  the 


-h3- 

top  of  the  picture  is  begun.  Finally  at  30,  a  9  bit  vertical  coincidence 
occurs  and  after  waiting  for  the  next  horizontal  drive  pulse  (indicating 
the  end  of  the  current  line)  the  process  stops  and  is  ready  to  begin  again 
at  32.   The  time  elapsed  from  C  to  D  is  one  frame  in  length  (l/30  second). 
At  this  time  if  the  pen  Enable  switch  is  still  activated  and  the  pen  is 
in  the  repetitive  coloring  mode,  a  new  pen  positon  is  accepted  and  the 
process  begins  anew.   In  the  single  coloring  mode,  the  Enable  switch  must 
be  released  and  reactivated  in  order  to  initiate  a  new  coloring  cycle. 

During  vertical  retrace,  the  left  and  right  point  registers  are 
set  equal  to  the  pen  position.   This  is  done  so  that  extraneous  coloring 
will  not  occur  should  the  system  fail  to  find  a  left  or  right  point  at  the 
top  of  the  figure.  Failure  to  find  a  point  can  result  from  there  being  no 
point  to  find  on  a  particular  line  or  because  of  the  outline  geometry  at 
the  top  of  the  figure.   In  Figure  13  A  and  B,  either  the  right  point  or 
the  left  point  is  coincident  with  the  horizontal  pen  position.   Under 
these  circumstances,  the  system  may  fail  to  find  either  the  right  or  left 
boundary.   Since  the  system  always  uses  the  last  retained  left  or  right 
point  unless  a  new  one  is  found,  failure  to  find  the  boundary  at  the  top 
means  that  the  left  or  right  point  which  was  used  at  the  bottom  will  be 
used  at  the  top.   Except  in  special  cases,  these  points  are  wrong  and 
frequently  can  result  in  coloring  outside  of  the  outline.   By  initializing 
to  the  pen  position,  the  coloring  is  kept  within  the  boundary. 

The  location  of  points  on  the  raster  of  the  system  are  deter- 
mined by  means  of  a  horizontal  and  a  vertical  counter.   The  horizontal 
counter  counts  the  output  of  an  oscillator  which  operates  at  about  8MHz. 
This  oscillator  is  voltage  controlled  so  that  its  frequency  varies  with 
disc  speed  changes  'which  occur  over  time  of  the  order  of  a  frame.   Precise 
tracking  is  not  necessary  since  stability  is  not  necessary  for  more  than 
about  one  line  (63 •  5  l-t  sec).   The  variation  in  disc  speed  during  this 


-kk- 


Top  of  outline 


Horizontal 
pen  position 


A.  Possible  failure  in  finding  right  point 


No  other  boundaries 
to  the  left         — <JTbp  of  outline 


Horizontal    pen    position 


B.  Possible  failure  in  finding  left  point 


Figure  13 .   Errors  in  Finding  the  Right  and  Left  Points 


-k5- 

time  is  about  70  nsec.  maximum.   The  horizontal  counter  is  reset  at  the 
end  of  each  line  by  the  horizontal  drive  signal.   Thus,  the  count  is 
initialized  to  zero  at  the  start  of  each  line.   This  produces  a  maximum 
uncertainty  between  two  successive  lines  of  62  nsec.  (1/2  of  the  clock 
period)  due  to  the  uncertainty  of  the  start  of  the  counter.   Considering 
this  with  the  variation  in  disc  speed  gives  a  maximum  variation  of  2 
counts  per  line  which  is  less  than  the  resolution  of  the  system. 

The  vertical  counter  counts  the  horizontal  drive  pulses  and  is 
reset  by  the  vertical  drive  pulse.   The  least  significant  bit  of  the 
vertical  counter  is  controlled  by  the  horizontal  counter  in  conjunction 
with  the  vertical  drive  pulse.   The  horizontal  counter  supplies  a  signal 
during  the  center  two  quarters  of  each  horizontal  line.   Depending  on 
whether  this  signal  is  present  or  not  when  the  vertical  drive  pulse  occurs, 
the  least  significant  bit  of  the  vertical  counter  is  either  set  to  a 
logical  zero  or  one.   Thus  the  least  significant  bit  determines  whether 
the  vertical  counter  contains  an  even  or  odd  count  corresponding  to  an 
even  or  odd  field.   The  scale  of  the  remainder  of  the  vertical  counter 
which  counts  horizontal  drive  is  then  two. 

Coordinates  corresponding  to  positions  on  the  display  are 
stored  as  counts  in  the  various  registers.   There  are  five  horizontal 
registers  and  three  vertical  registers.   Some  of  these  registers  are 
combined  with  coincidence  circuits  such  that  when  the  register  count 
corresponds,  to  the  counter  count  an  output  pulse  is  generated. 

The  horizontal  registers  are  the  horizontal  pen  register,  the  left 
point  register  (dual)  and  the  right  point  register  (dual) .   The  horizontal 
pen  register  stores  the  horizontal  coordinate  of  the  pen  position.   The 
upper  level  of  the  left  and  right  point  registers  store  the  left  and  right 
point  coordinates  to  be  used  in  coloring  on  the  following  television  line. 


-k6- 

The  lower  level  of  these  registers  contains  the  currently  used  left  and 
right  point  coordinates .   The  inf ormation  in  the  upper  level  is  shifted 
into  the  lower  level  during  horizontal  drive.   Both  lower  left  and  right 
point  registers  as  well  as  the  horizontal  pen  register  have  a  coincidence 
output . 

The  vertical  registers  are  the  vertical  pen  register,  the  top 
point  register  and  bottom  point  register.   The  vertical  pen  register  con- 
tains the  vertical  coordinates  of  the  pen  position.   The  top  and  bottom 
point  registers  contain  the  vertical  coordinates  of  the  top  and  bottom 
point.   All  of  these  registers  have  coincidence  outputs.   Figure  Ik   shows 
a  simplified  diagram  of  the  coloring  logic.   The  complete  coloring  logic 
may  be  found  in  the  Appendix.   As  can  be  seen  in  Figure  Ik,   the  actual 
color  signal  used  to  write  on  the  disc  is  the  result  of  Anding  the  hori- 
zontal and  vertical  color  duration  signals. 

In  the  simplified  diagram  of  Figure  1^,  the  horizontal  pen  register 
and  coincidence  does  not  perform  any  function.   In  the  actual  system  it 
is  used  in  determining  the  initial  starting  and  final  stopping  of  the 
coloring.   Its  primary  function,  of  course,  occurs  during  the  search  for 
the  top  and  bottom  points.   The  coincidence  is  a  seven  bit  coincidence 
rather  than  a  9  bit  coincidence  so  as  to  provide  a  fairly  wide  window 
during  the  search  for  the  top  and  bottom  point.   This  increases  the 
probability  of  finding  a  coincidence.   The  coloring  circuitry  as  well  as 
the  top  and  bottom  point  search  control  logic  is  discussed  in  detail  in 
the  Appendix. 


-hi- 


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Right  Point 
Register  and 
Coincidence 

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Figure  lU.   Simplified  Diagram  of  Coloring  Logic 


-Ii6- 

5.    DISCUSSION  OF  RESULTS,  SUGGESTED  IMPROVEMENTS  AND  CONCLUSIONS 

Only  one  unforseen  problem  occurred  in  the  final  system.   This  is 
the  so  -  called  "bleeding  problem. "  Recall  that  one  of  the  rules  for  the 
boundary  is  that  it  must  be  closed.   In  the  event  that  it  is  not  closed 
(i.e.  if  there  is  a  hole),  the  coloring  logic  will  not  find  a  boundary 
point  at  that  location.   This  is  usually  no  problem  since  under  these 
circumstances  the  system  reuses  the  point  which  it  used  previously.  Since 
the  boundaries  are  usually  slowing  varying  and  contain  only  a  few  holes, 
no  misregistration  of  the  coloring  results.   If  however,  there  is  another 
boundary  present  which  is  not  a  part  of  the  boundary  in  question  but 
which  does  have  a  point  on  the  particular  line  being  considered,  the 
system  will  then  take  this  point  to  be  the  boundary.   This  causes  the 
color  to  "bleed"  through  the  hole  in  the  outline.   This  is  shown  in  Figure 
15.   Of  course  this  is  precisely  what  the  system  is  supposed  to  do,  but 
it  is  usually  not  what  is  desired  by  the  operator. 

The  problem  arises  because  of  the  pen  writing  method  used.   Since 
the  pen  signal  is  generated  by  light  from  the  raster,  the  pen  produces  a 
signal  at  a  very  low  repetition  rate  (one  pulse  every  1/60  second).   In 
practice  it  is  easy  to  move  the  pen  past  more  than  one  raster  line  in 
this  time  and  thus  "skip"  some  lines.   This  leaves  holes  in  the  outline. 
These  holes  cause  no  problem,  of  course,  if  the  outline  is  simple.  For 
multiple  outlines  however  these  holes  cause  faulty  coloring.   Prevention  of 
holes  requires  considerable  care  in  drawing  the  outline.   One  solution 
to  this  problem  is  to  use  some  other  method  of  generating  the  pen  signal 
which  will  yield  a  higher  pen  pulse  rate.   This  is  not  a  very  useful 
approach,  however,  since  the  disc  can  be  written  on  only  at  the  1/60  pulse 
per  second  rate.   Another  solution  is  to  utilize  some  kind  of  gap  filling 
scheme.   A  third  is  to  allow  only  one  outline  to  be  drawn  at  a  time.   The 
best  solution  is  the  second  one  if  it  could  be  implemented. 


-1*9- 


Figure  15.   The  Bleeding  Problem 


-50- 

A  related  problem  which  occurred  was  that  of  leakage  at  the  top 
and  bottom.   This  occurred  because  of  the  difficulty  in  drawing  a  hori- 
zontal boundary  with  the  pen.  When  a  horizontal  line  is  written  with 
the  pen,  if  many  pulses  are  written  at  a  high  density,  the  disc  becomes 
magnitized  completely  in  one  direction  and  the  output  begins  to  decrease. 
When  this  happens  gaps  appear  at  the  top  and  bottom  of  the  figure's 
boundary.   If  another  boundary  occurs  above  or  below  the  gaps,  the  top 
and  bottom  point  search  may  "slip  through"  the  gap  and  find  the  wrong  top 
or  bottom  point.   This  is  shown  in  Figure  16.   This  problem  can  be  elimi- 
nated by  careful  use  of  the  pen  in  the  horizontal  direction  and  by  widening 
the  top  and  bottom  point  search  window  so  that  the  probability  of  a  point 
occurring  within  the  window  is  increased. 

As  mentioned  before,  neither  of  the  above  problems  manifests 
itself  if  the  outline  is  accurately  drawn  or  sufficiently  simple.   To  be 
simple  enough  requires  that  there  be  only  two  outline  points  on  any  one 
horizontal  line.   This  is  frequently  not  the  case,  of  course. 

It  is  possible  to  take  advantage  of  the  fact  that  if  no  new 
left  or  right  points  are  found,  the  old  ones  are  reused  in  this  system. 
One  can  easily  color  any  square  or  retangular  figure  by  simply  designating 
a  top  point,  a  bottom  point  and  any  left  and  right  points  which  are  required. 
In  other  words,  it  is  not  necessary  to  completely  close  the  figure  (if  it 
is  the  only  figure).   It  is  only  necessary  to  designate  one  top  and  one 
bottom  point  which  lie  on  the  same  vertical  in  order  to  define  the  extent 
of  the  figure  in  the  vertical  direction.   To  define  the  horizontal  extent 
it  is  sufficient  to  designate  a  left  or  right  point  only  on  those  lines 
for  which  the  horizontal  width  of  the  coloring  is  to  change.   Of  course, 
the  first  horizontal  line  must  be  defined  unless  one  desires  the  coloring 
to  be  only  as  wide  as  the  initializing  circuitry  permits.   Clearly,  this 
only  works  for  figures  which  are  aligned  with  the  scanning  line. 


■51- 


Top  Leakage 


Bottom  Leakage 


Figure  16.   Leakage  Through  a  Gap 


-52- 


There  are  some  changes  which  could  possibly  yield  improvements 
in  performance  in  future  devices  like  the  Tricolor  Cartograph.   Stabilizing 
the  disc  speed  -would  allow  more  stable  operation  of  the  display  and  the 
processor.   As  mentioned  above,  perhaps  some  other  type  of  pen  could  be 
used  to  advantage  in  order  to  improve  the  type  of  outline  which  is  obtained. 
Possibly  outlines  could  be  input  directly  from  a  television  camera  which 
is  synchronized  to  the  disc.   Then  line  drawings  of  things  to  be  colored 
could  be  made  with  black  ink  on  white  paper  and  input  by  this  means.   In 
addition,  an  automatic  erase  feature  could  be  implemented  so  that  selected 
areas  can  be  automatically  erased  just  as  they  are  automatically  colored 
now.  A  higher  resolution  disc  would,  of  course,  yield  a  higher  quality 
picture  and  allow  the  use  of  a  higher  chopping  frequency.   The  use  of  a 
higher  chopping  frequency  would  give  a  more  uniform  colored  area.   If  a 
high  frequency  chopping  signal  can  be  recorded  on  the  disc,  the  problem 
of  maintaining  the  dot  interlace  over  the  entire  frame  can  be  eliminated. 
This  would  be  accomplished  by  recording  the  interlaced  chopping  signal 
right  on  the  disc.   Then  the  horizontal  and  vertical  drive  signals  could 
be  generated  from  this  chop  track  by  using  counters  or  a  separate  sync 
track  which  is  synchronized  to  the  chopping  track  could  be  used.   Finally, 
the  addition  of  shades  of  gray  would,  of  course,  add  more  variety  to  the 
colors  obtainable  with  the  system. 

The  Tricolor  Cartograph  proved  itself  to  be  a  very  successful 
investigation.   The  coloring  method  used,  although  it  results  in  a  two 
line  misregistration,  results  in  very  adequate  colored  areas.   The  mis- 
registration which  occurs  is  not  noticable.   The  concept  of  using  a  local 
storage  media  which  is  capable  of  storing  large  amounts  of  pictorial 
coloring  information  was  demonstrated  to  be  feasible.   Assuming  further  im- 
provements in  resolution,  the  disc  appears  to  be  an  ideal  storage  media  for 


-53- 

this  purpose.   Also  demonstrated  is  the  concept  of  performing  a  reasonably- 
complex  operation,  the  coloring  of  closed  areas,  at  a  display  console  as 
opposed  to  performing  a  specialized  operation  such  as  this  with  a  general 
purpose  digital  machine.   In  addition,  the  automatic  coloring  was  imple- 
mented in  a  reasonably  simple  manner.   Improvements  in  the  resolution  of 
discs  and  reductions  in  the  complexity  of  color  display  tubes  in  the  next 
few  years  will  make  moderate  cost  high  resolution  color  display  terminals 
with  special  purpose  processing  capabilities  a  useful  reality. 


-5U- 


APPENDIX 


-55- 


Al.O  LOGIC  DESCRIPTIONS 


Al.l  Control  and  Video  Logic 

Figure  17  shows  the  Control  and  Video  logic  except  for  the 
coloring  logic  which  will  be  discussed  in  Section  A1.2. 

All  control  signals  and  power  enter  on  J31.   The  control  signals 
originate  at  the  push  buttons  on  the  front  of  the  display  console.   These 
control  signals,  except  the  Outline  Erase  and  Color  Erase  signals,  go  to 
the  Switch  Matrix  logic  A-l  where  they  are  combined  to  form  the  required 
signals  for  writing  and  erasing  in  the  appropriate  color.   An  example 
would  be  the  erase  red  signal,  R(ER),  where  ER  indicates  pen  erase  or 
total  erase.   The  Total  Erase  Control  A3  generates  a  one  frame  gate  pulse 
for  erasing  an  entire  track  of  the  disc.   The  Total  Erase  Control  circuit 
is  triggered  by  either  Cl-1  for  the  Color  Erase  operation  or  Cl-U  for  the 
Outline  Erase  operation.   An  explanation  of  the  Total  Erase  Control 
circuit  will  be  found  in  Appendix  Section  2.1.   The  outputs  of  both  of 
these  circuits,  Al  and  A3,  provide  signals  to  the  logic  which  drives  the 
Logic  to  Video  Converters  A4  and  A10.  Ak   and  A10  drive  the  four  erase 
and  four  write  inputs  to  the  disc.   The  pen  pulse  enters  the  control  at 
J23  and  is  shaped  at  A15.   It  then  passes  to  the  video  adders  A19,  20 
and  21  as  well  as  to  the  video  to  Logic  Converter  AI7.   At  the  Video  Adders 
A19,  20,  and  21,  the  pen  signal  is  added  into  the  red,  green  and  blue  video 
signals  so  that  it  will  be  displayed  on  the  monitor  screen  as  a  white 
reference  dot.   At  AI7  the  video  pen  pulse  is  converted  to  a  logic  pulse 
so  that  logic  operations  may  be  performed  on  it.   The  logical  pen  pulse 
ultimately  performs  two  functions:  writing  or  erasing  in  the  memory  and 
initialization  of  the  coloring  operation.   The  enable  signal  from  the  pen 
enters  at  J31-T  and  passes  through  A3  where  it  is  locked  out  during  total 
erase.   From  A3  it  proceeds  to  Cl-9.   This  is  a  delay  flip  flop  which 


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Figure  17.   Control  and  Video  Logic 


-57- 

delays  the  opening  of  the  pen  gate  until  the  switch  noise  from  the  Enable 
switch  has  passed.   This  is  necessary  since  the  pen'  preamplifier  is  satur- 
ated by  the  switch  noise  thus  producing  spurious  pen  pulses.   After  delay, 
Cl-12  is  triggered.   This  sets  pen  gate  flip  flop  (l)  allowing  pen  pulses 
through  gate  A13-C.  Flip  flop  (2)  prevents  successive  coloring  operations 
even  though  the  enable  button  may  be  depressed  when  the  single  multiple 
switch  is  in  the  single  position.   Vertical  and  horizontal  drive  enter  at 
ji+5  and  Jh6   respectively  and  are  converted  to  logic  levels  by  the  level 
shifters  Bl-2  and  7-   Control  of  the  chopper  is  performed  by  the  mode 
switch  A8-7.   The  chopper  is  normally  activated  when  a  pen  pulse  is  re- 
ceived in  the  color  mode  of  operation.   It  can,  however,  be  activated  by 
placing  the  Set-Up,  Operate  switch  in  the  Set-Up  position.   This  allows 
the  chopper  to  be  run  for  adjustment  purposes. 

The  video  signals  for  the  monitor  originate  at  the  red,  green  and 
blue  video  adders,  Aly,  20  and  21.   Here  the  red,  green  and  blue  video 
signals  from  the  disc  entering  at  J^O,  kl   and  h2.   are  added  to  the  pen 
pulse  from  the  pen  shaping  circuit  and  the  outline  video  signal  coming 
from  the  disc  at  J^3»   This  allows  equal  signals  from  the  pen  and  the  out- 
line memory  on  each  of  the  three  colors  and  thus  they  appear  white  on  the 
display.   The  outline  video  entering  at  Jl+3  passes  through  a  delay  line 
before  going  to  the  adders.   The  undelayed  signal  passes  directly  to  the 
Video  to  Logic  converter  AI7-IU  where  it  is  converted  to  logic  levels  and 
used  in  the. coloring  logic.   The  delay  is  required  in  order  to  bring  about 
registration  of  the  outline  with  the  colored  interior  of  the  outline.  With 
no  delay,  the  interior  lags  the  outline  due  to  delays  in  the  coloring 
circuitry. 

B2  is  the  horizontal  oscillator,  B3  the  horizontal  counter  and  Bk 
the  horizontal  buffer.   Similarly,  BlU  is  the  vertical  counter  and  B15 
the  vertical  buffer.   The  outputs  of  these  two  buffers  drive  the  inputs  of 


-5* 

all  the  register  and  coincidence  circuits  used  in  the  coloring  logic.   The 
least  significant  bit  from  the  horizontal  buffer  also  goes  to  gate  A7-10 
where  it  chops  the  pen  signal  when  writing  a  color.   This  helps  alleviate 
the  problem  of  overrecording  when  writing  in  a  color  with  the  pen.   This 
is  not  done  in  the  outline  writing  mode  because  it  interferes  with  the 
writing  of  a  good  outline.   See  the  discussion  of  pen  problems  in  Section  5, 

The  Horizontal  Oscillator  produces  an  8MH  clock  signal  which  is 
counted  by  the  Horizontal  Counter.   This  signal  appears  at  B2-B  and  enters 
the  counter  at  B3-13*   Horizontal  drive  enters  the  counter  at  B13-12.   It 
is  used  to  reset  the  counter  each  horizontal  line.   The  Horizontal  Counter 
produces  two  signals  in  addition  to  the  18  flip  flop  outputs.   The  first 
of  these  is  the  AFC  pulse.   This  pulse  is  fed  back  to  the  oscillator  to 
provide  some  degree  of  frequency  control.   The  second  is  the  field  sync 
pulse.   This  signal  goes  to  the  Vertical  Counter  where  it  controls  the 
state  of  the  least  significant  bit  of  that  counter.   This  is  done  so  as  to 
keep  the  Vertical  Counter  referenced  to  the  proper  field  of  the  television 
frame.   The  field  sync  pulse  is  the  logical  exclusive-or  of  the  two  most 
significant  bits  of  the  Horizontal  Counter.   This  pulse  then  exists  during 
the  center  two-fourths  of  each  television  line.   If  the  vertical  drive 
pulse  occurs  during  this  field  sync  pulse,  then  the  next  field  is  even 
and  the  least  significant  bit  is  set  to  zero.   If  the  vertical  drive  pulse 
occurs  other  than  during  the  field  sync  pulse,  the  least  significant  bit 
is  set  to  a  one  to  indicate  the  beginning  of  an  odd  field. 

The  signal  appearing  at  B2-D  is  the  clock  signal  of  the  Horizontal 
oscillator  but  it  is  shifted  in  phase  180  from  the  signal  driving  the 
counter.   This  signal  is  used  in  the  coloring  logic  in  order  to  accomplish 
synchronous  dumping  of  the  contents  of  the  Horizontal  Counter  into  the 
horizontal  registers. 


-59- 

The  Vertical  Counter  (with  "Che  exception  of  the  least  significant 
bit)  counts  the  horizontal  drive  pulses  from  the  disc.   The  vertical  drive 
pulse  causes  this  counter  to  reset  at  the  end  of  each  field. 

The  7  bit  Vertical  Pen  Register  and  Coincidence  circuit  and  the 
9  hit  Horizontal  Pen  Register  and  Coincidence  circuit  provide  output 
pulses  which  indicate  the  last  horizontal  and  vertical  position  of  the 
pen.   This  output  is  not  used  at  present. 

The  Indicator  A2  provides  an  indication  that  the  control  signals 
generated  at  the  Display  Console  have  been  properly  received  at  the 
Processor. 

Al. 2  Coloring  Logic 

The  coloring  logic  is  shown  in  Figure  18.   The  coloring  logic  is 
a  mixture  of  synchronous  and  asynchronous  logic.   As  described  in  Section 
k.6.3)   there  are  five  horizontal  and  three  vertical  registers.   The  hori- 
zontal registers  are  B7  (dual  register),  B8,  BIO,  and  Bll.   The  dual 
register  B7  stores  the  left  and  right  boundary  points  as  they  are  found. 
These  are  then  shifted  into  the  register  and  coincidence  circuits  B8  and 
BIO  whose  outputs  control  the  Horizontal  Color  Duration  flip  flop  (8) . 
This  flip  flop  controls  the  length  of  the  coloring  in  the  horizontal 
direction.   It  is  set  by  the  output  of  the  Horizontal  Left  Point  Register 
and  Coincidence  circuit  B8.   It  is  reset  by  the  output  of  the  Horizontal 
Right  Point,  Register  and  Coincidence  circuit  BIO.   It  can  also  be  reset 
by  horizontal  drive  if  for  some  reason  the  right  point  coincidence  fails 
to  occur.   This  prevents  the  coloring  from  continuing  beyond  the  end  of 
the  current  line . 

Since  a  left  point  cannot  occur  to  the  right  of  a  right  point,  (8) 
cannot  be  set  once  the  right  point  has  been  passed.  This  is  accomplished 
at  C2-2  by  means  of  flip  flop  (20).   Flip  flop  (20)  is  reset  by  hori- 


■6o- 


0     ©     0     © 


©       ©       ©       ©       ©       ®       © 


•mi«who  )imi  -tettmao  am*  «•»  u*  • 


Figure  18.      Coloring  Logic 


-61- 

zontal  drive  and  set  by  right  point  coincidence.   In  addition  to  this 
signal,  flip  flop  (8)  also  cannot  be  set  during  horizontal  drive  (when 
the  registers  are  changing)  or  while  it  is  being  reset  (as  might  occur 
when  the  left  and  right  points  are  the  same).   These  two  functions  are 
accomplished  at  C2-5  and  C2-6  respectively. 

Register  Bll  is  the  Horizontal  Pen  Register  and  Coincidence  circuit. 
This  register  stores  the  horizontal  coordinates  of  the  light  pen  during 
the  coloring  operation.   In  addition,  a  pulse  is  generated  by  it  each 
time  the  contents  of  the  horizontal  counter  is  identical  to  the  contents 
of  the  register.   This  output  pulse  fulfills  several  functions  in  the 
system.   First,  it  is  used  to  initialize  the  Left  and  Right  Point  Registers 
during  vertical  drive.   This  is  accomplished  at  B6-X  and  N  and  Cl-T  and 
B6-13.   The  pulse  sent  to  the  Right  Point  Register  is  delayed  from  that 
sent  to  the  Left  Point  Register  by  using  the  inverted  coincidence  signal 
(B9-16)  in  conjunction  with  the  One  Shot  Cl-15.   By  delaying  the  right 
point,  the  left  and  right  points  are  prevented  from  assuming  the  same  values. 
This  in  turn  prevents  uncertainty  in  the  state  of  the  Horizontal  Color 
Duration  flip  flop  should  the  system  fail  to  find  a  left  and  right  point 
at  the  top  of  the  colored  area.   The  second  function  for  which  the  Hori- 
zontal Pen  Coincidence  is  used  is  in  the  determination  of  the  top  and 
bottom  points.   This  is  done  at  C^-M,  N,  P  and  C4-V,  U  and  W.   At  these 
two  gates  the  outline  pulses  which  are  coincident  with  the  horizontal  pen 
coincidence-  are  channeled  to  the  appropriate  storage  flip  flop  (3)  or  {h) . 
Which  of  these  flip  flops  is  set  is  controlled  by  the  Point  Search  Control 
flip  flop  (2).   This  flip  flop  controls  whether  the  top  point  gate  or  the 
bottom  point  gate  is  open.   Once  a  bottom  point  is  found,  the  appropriate 
flip  flop,  (3)  is  set  and  no  further  search  for  that  point  takes  place. 


-62- 

This  is  accomplished  by  having  the  flip  flop  itself  close  the  gate.   For 
the  top  point,  the  gate  is  not  closed  until  a  top  point  is  found  (signified 
by  (k)   being  set)  and  the  8  bit  vertical  coincidence  occurs.   In  this  way. 
all  points  are  accepted  starting  from  the  top  of  the  picture  on  down 
until  the  vertical  pen  position  is  reached.   The  top  point  search  ceases 
when  flip  flop  (5)  is  set.   The  pulses  which  set  the  top  and  bottom  point 
flip  flops  also  dump  the  vertical  counter  into  the  top  and  bottom  point 
registers  B-19  and  B-l8.   If  a  top  or  bottom  point  signal  has  not  been 
found  when  the  counter  Cll  times  out,  the  No  Bottom  Point  or  No  Top  Point 
flip  flops  (15)  and  (16)  are  set  and  appropriate  indicators  light  showing 
why  the  coloring  failure  occurred.   The  Point  Search  Control  flip  flop 
(2),  as  mentioned  earlier,  controls  which  point  is  being  sought.   This  is 
accomplished  by  having  this  flip  flop  in  the  set  state  between  vertical 
drive  and  vertical  pen  coincidence  (upper  part  of  figure)  and  having  it 
in  the  reset  state  between  vertical  pen  coincidence  and  vertical  drive 
(lower  part  of  figure).   The  two  outputs  control  the  routing  of  the  co- 
incidence pulses  to  the  appropriate  registers  and  flip  flops.   This  coin- 
cidence signal  is  generated  at  C2-A,  B,  E,  F,  and  D.   At  this  gate  the 
logical  Nand  of  the  start  flip  1,  the  horizontal  pen  coincidence,  the  out- 
line and  the  not  side  of  the  End  Point  Search/Begin  Coloring  flip  flop  is 
formed.   The  essential  combination  is  that  of  the  outline  and  the  hori- 
zontal pen  coincidence.   The  other  signals  are  present  for  control  purposes. 
Flip  flops.  (7)  and  (9)  control  the  left  and  right  point  dump.   These 
flip  flops  are  both  reset  by  horizontal  drive.   When  a  line  is  scanned, 
the  Left  Point  Stored  flip  flop  remains  reset  until  the  horizontal  pen 
coincidence  occurs.   During  this  time  any  outline  pulse  which  occurs 
causes  the  Horizontal  Counter  to  be  dumped  into  the  Left  Point  Register 
B7  by  the  Left  Point  Dump  flip  flops  18  and  19.   Once  the  horizontal  pen 


-63- 

coincidence  has  occurred,  (7)  is  set  and  outline  pulses  are  allowed  to 
pass  to  the  right  point  logic.   The  first  pulse  after  horizontal  pen  co- 
incidence causes  the  right  point  dump  flip  flop  (17)  to  dump  the  hori- 
zontal counter  contents  into  the  Right  Point  Register  B7.  At  the  same 
time  (9)  is  set  and  the  right  point  gate  is  closed.   The  flip  flop  (17) 
stores  the  fact  that  a  right  point  has  occurred.   On  the  next  clock  pulse 
after  (17)  is  set,  the  counter  is  dumped  into  the  register.   This  synchro- 
nizing circuit  is  required  to  prevent  the  counter  from  being  dumped  while 
its  contents  are  changing.   The  left  point  dumping  circuit  (l8  and  19) 
is  more  complicated  than  the  right  point  dumping  circuit.   This  is  because, 
whereas  there  is  only  one  right  point,  there  is  a  whole  succession  of 
left  points  the  last  of  which  must  be  retained.   Thus  flip  flop  (l8)  ac- 
knowledges the  occurrence  of  a  left  point  and  sets  flip  flop  (19)  while 
at  the  same  time  locking  out  future  pulses.   (19)  remains  set  until  the 
next  clock  pulse  at  which  time  the  left  point  is  dumped  and  both  (l8)  and 
(19)  reset  so  that  the  next  pulse  can  be  accepted.   Because  of  the  high 
speed  of  the  horizontal  counter  it  is  necessary  that  the  horizontal 
registers  be  filled  synchronously.   This  is  not  the  case  with  the  vertical 
registers  and  they  are  filled  asynchronously. 

As  mentioned,  there  are  three  vertical  registers:   the  Vertical 
Pen  Register  Bl6,  the  Vertical  Bottom  Point  Register  Bl8  and  the  Vertical 
Top  Point  Register  B19.   These  are  all  8  bit  registers  with  8  bit  coin- 
cidence outputs.   The  Vertical  Pen  Register  stores  the  vertical  coordinate 
of  the  pen  position  and  gives  a  coincidence  pulse  whenever  its  contents 
are  identical  to  the  vertical  counter.   Since  the  vertical  registers  are 
all  8  bit  registers,  the  coincidence  pulses  produced  by  them  occur  every 
field.   A  9  bit  coincidence  is  formed  at  C5-P  by  using  the  coincidence  of 
the  least  significant  bit  and  the  output  of  the  8  bit  coincidence  circuit. 


-6k- 

The  8  and  9  bit  Vertical  Pen  Coincidence  signals  are  used  to  perform 
various  control  operations  in  the  system.   The  coincidence  outputs  of  the 
top  and  bottom  point  registers  control  the  Vertical  Color  Duration  flip 
flop  (10).   This  flip  flop  is  set  by  vertical  9  bit  coincidence  or  vertical 
drive  or  vertical  bottom  point  coincidence.   In  its  normal  sequence  of 
operation  it  is  set  first  by  a  9  bit  vertical  coincidence  whereupon  the 
bottom  of  the  figure  is  colored.   Next  it  is  reset  by  bottom  point  coin- 
cidence.  Then  it  is  set  again  by  top  point  coincidence  (the  other  field) 
and  reset  by  bottom  point  coincidence.   Finally,  it  is  set  by  top  point 
coincidence  and  then  the  whole  process  is  terminated  at  9  bit  vertical  co- 
incidence again.   Flip  flop  (21)  prevents  the  Color  Duration  flip  flop  (10) 
from  being  set  if  the  bottom  point  has  already  been  passed.   In  addition, 
the  set  input  is  locked  out  by  the  reset  input  and  the  flip  flop  is  reset 
by  vertical  drive.   These  three  precautions  are  necessary  to  prevent 
erroneous  coloring  if  the  top  and  bottom  point  positions  should  become 
interchanged,  i.e.  the  top  point  is  below  the  bottom  point. 

Now  that  the  individual  functional  groups  of  the  coloring  logic 
have  been  explained,  a  description  of  one  complete  coloring  cycle  will  be 
given.   This  will  explain  the  sequential  operation  of  the  system  and 
indicate  the  function  of  the  control  logic  as  yet  unmentioned. 

The  cycle  starts  with  a  pen  pulse  at  B6-5-   This  causes  the 
horizontal  and  vertical  coordinates  of  the  pen  to  be  stored  in  the  hori- 
zontal and  vertical  pen  registers  Bll  and  Bl6.   At  the  same  time  the  Start 
flip  flop  (l)  is  set  and  the  Stop  flip  flop  (lU)  is  reset.   Setting  the 
Start  flip  flop  opens  gate  C2-ABEDF  allowing  outline  pulses  which  are  co- 
incident with  the  horizontal  pen  position  to  pass  to  the  top  and  bottom 
point  search  logic,  explained  previously.   It  also  locks  out  future  pen 


-65a- 

pulses  and  triggers  the  one  shot  Cl-6  which  resets  the  No  Top  Point  and 
No  Bottom  Point  flip  flops.   The  Stop  flip  flop  closes  gates  C9-13,  Ik, 
12  and  C9-15,  16,  17.   Thus  stopping  the  flow  of  reset  pulses  which  have 
kept  flip  flops  1,  2,  3>  ^->  5,  6,  and  12  as  well  as  counter  Cll  reset. 
At  the  same  time  it  allows  counter  Cll  to  commence  counting  vertical  drive 
pulses .  Recall  that  Cll  allows  7  fields  for  finding  the  top  and  bottom 
points.   If  no  top  and  bottom  point  are  found  in  7  fields  the  entire  pro- 
cess is  terminated  by  the  signal  at  C10-L  which  gates  the  proper  infor- 
mation into  the  No  Top  Point  and  No  Bottom  Point  flip  flops  at  C8-S  and  R 
and  resets  the  Stop  flip  flop  at  C9-P.   If  both  the  top  and  bottom  points 
are  found  a  signal  is  generated  at  C8-E.   This  signal  stops  the  counter 
Cll  at  CIO- 20  and  allows  flip  flop  (6),  the  End  Point  Search /Begin  Coloring 
flip  flop  to  set  at  the  next  9  bit  vertical  coincidence.   This  flip  flop 
closes  gate  C2-ACEDF  and  locks  out  its  own  set  input.   It  also  opens  gates 
C8-3,  k,   5  and  C8-6,  7,  8.  The  signal  at  C8-3,  h,   5  causes  the  Vertical 
Color  duration  flip  flop  (10)  to  set  for  the  coloring  of  the  lower  half 
of  the  figure  as  explained  previously.   The  signal  at  C8-7  allows  the  next 
vertical  drive  pulse  to  set  flip  flop  (13) ,  the  Field  Lapse  flip  flop. 
This  flip  flop  simply  senses  the  fact  that  one  field  has  elapsed  since 
the  flip  flop  (6)  was  set.   In  other  words  it  inhibits  pulses  at  C10-F 
until  both  fields  of  the  frame  have  been  colored.   The  vertical  color 
duration  logic  operates  as  explained  previously.   The  Vertical  Color  Dur- 
ation flip  flop  (10)  opens  gate  C8-9,  10,  11.   This  allows  flip  flop  (11), 
Horizontal  Line  Lapse  to  be  set  when  the  next  horizontal  pen  coincidence 
pulse  occurs.   It  also  opens  gate  C3-CDE  allowing  outline  pulses  to  pass 
to  the  horizontal  color  duration  circuitry.   It  also  has  the  effect  of 
removing  the  reset  signal  from  flip  flops  (11)  and  (12).   Once  (11 )  has 
been  set,  (12)  will  be  set  by  the  next  horizontal  drive  pulse.   Thus,  the 
effect  of  (ll)  and  (12)  is  to  introduce  a  one  line  delay  before  the  actual 


-65b- 

coloring  begins.   This  accomplishes  two  things:  First,  it  allows  the 
horizontal  color  duration  logic  to  find  some  left  and  right  points  and 
second,  it  causes  the  coloring  to  fall  within  the  outline.   Thus,  the 
actual  coloring  signal  is  formed  at  C^-K  and  consists  of  the  logical  Nand 
of  the  Color  Control  flip  flop  (12)  (which  is  just  flip  flop  (10)  delayed 
from  starting  by  one  line)  and  the  horizontal  color  duration  signal  from 
flip  flop  (8)  as  already  explained.   The  cycle  now  continues  under  the 
control  of  the  Vertical  Color  Duration  flip  flop  (10)  until  the  next  9 
bit  vertical  coincidence  pulse  occurs  (one  frame).   This  signal  appears 
at  C10-H.   After  this  signal  is  generated,  at  the  next  horizontal  pen 
coincidence  the  Stop  flip  flop  (lU)  is  set.   The  cycle  continues  until 
the  next  horizontal  drive  pulse  at  which  time  all  the  flip  flops  1,  2,  3? 
k,    5,  6,  11,  12  and  13  are  reset.   Note  that  (ll)  and  (12)  are  reset  by 
virtue  of  (6)  being  reset.   During  coloring,  the  color  signal  generated 
at  C9-K  passes  to  A7-U,  A7-N  and  is  then  routed  through  one  or  more  of 
the  color  selection  gates  A7-E,  F,  K  and  on  to  Logic  to  Video  Converter 
A10.   This  completes  the  description  of  the  coloring  logic. 


-66- 


A2.0  CIRCUIT  DESCRIPTIONS 


In  this  section  a  brief  circuit  description  will  be  given  for 
each  printed  circuit  board  and  major  chassis. 

A2.1  Circuit  Boards 

The  circuit  boards  are  discussed  in  order  by  number.   The 
schematics  of  these  circuits  are  given  at  the  end  of  this  section.   All 
digital  integrated  circuits  are  Texas  Instruments  Series  'jk'N. 

1^69-121  Pen  Preamplifier 

This  is  a  two  stage  high  pass,  high  gain  amplifier  used  in  the 
pen  to  amplify  the  output  of  the  light  sensitive  diode.   The  Enable  switch 
is  also  located  on  this  circuit  board. 

1^69-133  Counter  Buffer 

This  circuit  has  2-input  nand  integrated  circuits  connected  as 
inverters.   It  is  used  to  buffer  the  output  of  the  horizontal  and  vertical 
counters . 

Ik69-13k       Horizontal  Counter 

A  9-bit  synchronous  counter  utilizing  J-K  flip  flops. 

11+69-135  Dual  9-Bit  Register 

A  dual  9-t>it  clocked  register  utilizing  D-type  flip  flops. 

1469-136  8-Bit  Register  and  Coincidence 

An  8-bit  clocked  register  utilizing  D-type  flip  flops  whose  out- 
puts are  connected  to  a  digital  comparator  circuit  which  utilizes  And- Or - 
Invert  type  logic  circuits . 


-67- 

1469-137  R-S  Flip  Flop 

Several  nands  connected  to  form  R-S  flip  flops. 

IU69-I38  Vertical  Counter 

A  9-bit  synchronous  counter  utilizing  J-K  type  flip  flops . 

1U69-139  9-bit  Register  and  Coincidence 

The  same  as  the  8  bit  circuit  except  with  an  added  bit. 

lk6S-lkO     Switch  Matrix 

A  decoder  for  the  control  switches  which  generates  the  logical 
combinations  of  the  control  switch  signals  required  by  the  processor. 

11*69-11+1  2-bit  Coincidence  and  R-S  Flip-Flop 

Several  nand  connected  as  R-S  flip  flops  as  well  as  a  D-type 
flip  flop  and  And-Or-Invert  circuit  connected  as  a  1  bit  register  and 
comparator.   Used  to  form  a  9-t>it  coincidence  from  an  8-bit  coincidence 
and  a  1  bit  input. 

1469-11*5  Total  Erase  Control 

Logic  to  generate  a  one  frame  erase  signal  as  well  as  perform 
certain  lockout  functions. 

1U69-156  Level  Shifter 

Shifts  the  video  drive  signals  (about-1*  volts)  to  logic  levels 
(-5  volts) . 

11*69-159  One  Shot  Buffer 

A  group  of  nands  connected  as  monostable  multivibrators .   Both 
a  complemented  and  an  uncomplemented  signal  are  available. 


-68- 

Ik69-l6l     General  2- Input  Nand 

Three  2- input  nand  packages  with  all  pins'  brought  out. 

1U69-162  General  3- Input  Nand 

Three  3-input  nand  packages  with  all  pins  brought  out. 

1U69-173  Switch  Filters 

A  group  of  RC  low  pass  filters  for  the  control  switches. 
1^69-175  Logic  to  Video  Converter 

A  very  fast  direct  coupled  switch  which  converts  the  -5  volt 
to  0  volt  logic  levels  to  a  9  to  +1  volt  video  level. 

1^69-176  Indicator 

An  array  of  9  light  bulbs  with  drivers  such  that  a  zero  volt 
signal  lights  the  bulb  and  a  -5  volt  signal  extinguishes  it. 

1469-177A  Video  to  Logic  Converter 

A  very  fast,  very  high  gain  direct  coupled  level  shifter  with 
adjustable  input  threshold  which  will  convert  a  0  to  +0.3  volt  video 
signal  to  a  0  to  -5  volt  logic  signal. 

li+69-178  +1  Volt  Supply /Mode  Switch 

Supplies  +1  volt  and  provides  a  switch  which  converts  the  logic 
level  input  to  the  level  required  by  the  chopper  control  input  on  the  disc, 

1U69-179  Pen  Shaper  and  Gate 

Converts  the  pen  pulse  into  a  very  fast  +1  volt  pulse  about 
100  nsec  wide.   Also  provides  a  logic  gate  output  which  begins  with  the 
pen  pulse  and  lasts  for  several  hundred^  seconds. 


-69- 

1469-180  3- Input  Video  Adder 

This  circuit  combines  three  separate  video  input  signals  into 
one.   Separate  gain  adjustment  is  provided  for  each  signal  as  well  as 
overall  gain.   It  is  direct  coupled  and  wide  band. 

1469- l8l- 20  General  4- Input  Nand 

Three  4- input  nand  packages  with  all  pins  brought  out. 

l469-l8l-70  General  J-K  Flip  Flop 

Three  J-K  Flip  Flop  packages  with  all  pins  brought  out. 

1469-184  Voltage  Controlled  Oscillator 

A  Colpitts  oscillator  with  a  varactor  diode  in  the  tank  circuit, 
A  pulse  width  to  voltage  converter  produces  a  control  voltage  dependent 
on  the  incoming  pulse  width.   The  maximum  shift  is  about  15  kHz  /usee  and 
is  adjustable  by  means  of  the  gain  adjustment. 

A2.2  Chassis 

The  following  is  a  brief  description  of  each  of  the  major 
chassis.   Following  the  descriptions  the  schematics  are  shown. 

A2.2.1  Main  Junction  Box 

The  Main  Junction  Box  serves  as  a  control  and  power  distri- 
bution center  for  the  Main  Console. 

A2.2.2  Display  Junction  Box 

The  Display  Junction  Box  serves  as  a  control  and  power  distri- 
bution center  for  the  Display  Console.  In  addition  the  pen  thresholding 
and  amplifying  circuit  is  located  in  it. 


-70- 

A2 . 2 . 3  Miscellaneous 

The  other  major  major  chassis  are  the  Circuit  Breaker  Panel, 
the  Modular  Power  Supplies  and  the  Switch  Panel.   The  Circuit  Breaker 
Panel  serves  as  an  AC  distribution  point.   The  Modular  Power  Supplies 
provide  -5,  +10,  and  +25  volt  DC  sources  for  all  of  the  circuitry.   The 
Switch  panel  contains  the  Control  Switches  which  are  used  to  select  the 
operating  modes  of  the  system. 


1469-121  PEN  PREAMPLIFIER 


-71- 


o 

+ 


Q 

5 

!     2 

A  ID 

P       O       < 

g   5   5 

0      9 


n 


t 


4>> 


# 


O 

■H 


UJ 


UJ< 


o 

UJ 

C 

8 

0. 

en 

{8 

UJ 

-J 
z 

* 

to 

* 
oo 


u.  c/> 
o  </> 

qq.  a: 


*  H§H 


UJ 

Q 

g 

Q 
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Figure  19 .      Pen  Preamplifier     11+69-121 


in 

m 


bJ 


3 
CD 

cc 

UJ 

F 

z 

O 

o 


18  ^ 

lie 
Ifrj 


°«5 


"s. 


■*>1 


°* 


?>"- 
*<■= 


2k. 

— 1    o 

B5 


2k 


2k 


7\' 


? 


-L. 


3 — c 


IB] 


1^ 


2k 


2k 


■a 


ra 


2k 


Zn 


2k 


ca 


7s 


j — c 


7v 


3 — c 


Ed 


*' 


■0 


-72- 


Figure  20.   Counter  Buffer  1U69-133 


-73- 


Figure  21.   Horizontal  Counter  -1469-134 


-7k- 


000000000® 


s  l 


2  5 


Figure  22.  Dual  9-Bit  Register  1^69-135 


-75- 


Figure  23.   8-Bit  Register  and  Coincidence  1U69-136 


l 
CD 


9 


CO 

I 
cr 

I 
o 


<> 


?>> 


6% 
co9> 


n. 


3-k> 


10  ^5 


<?* 


<E 


o*<: 


my 


co>^F 


jd 


■=F 


4? 


a 


F 


F 


.d 


Fj 


o 

-0|0 


-76- 


-0|O 


-0|O 


-OlO 


XJ 


F 


13 


F 


^ 


JJ 


F 


F 


n 


X3 


Fl 


F 


D3 


=       OlO 


-OlO 


-OlO 


-OlO 


-OlO 


= Oio 


Figure   2k.      R-S  Flip  Flop     II+69-I37 


Ibd    ■     ■  j  i.  j 

-a 


;fe 


sfe 


1 

J  1 

i         L 

L                 «. 

.       i 

1  - 

* 

a 

•   J 

X 

y 

■ 

m 

a 

r 

r. 

9 

g 

«■ 

-\ 

J>< 

Hf- 

c 

1 1 

J  ft 


ep: 


r 


B^ 


© 


E* 


™ 


© 


w 


0 


© 


0^ 


a 


© 


e 


© 


@ 


© 


Bit 


0 


a 


© 


E# 


a  S 


n 


SjJ 


Eft 


-  E? 


Eft 


Q 


A 


Eft 


2. 


T 


l-f 


a 


£1 


s 


£ 


x         a 


0 


■© 


-77- 


Figure  25.   Vertical  Counter  1469-138 


■78- 


Figure  26.   9-Bit  Register  and  Coincidence  1U69-139 


■79- 


Figure  27.   Switch  Matrix  li+69-l^O 


(0 


V) 
Q. 

3 

u. 


Ll) 

9 
o 

z 

o 
o 


z  aaoisV-r 


-80- 


■1  3M0KVrr  — 


Figure  28.   2-Bit  Coincidence  and  R-S  Flip  Flop  lU69-lUl 


(03)(,3OK 
(03)(,30)^ 


o 


o 
o 

Ld 
< 
UJ 


< 

o 


I 


(Q3)(,30)<- 


Figure  29.   Total  Erase  Control  Ik69-lh5 


A.T.C.   LEVEL   SHIFTER    1469-156 


22  pf 

if 


2.2  K 


IN>— * VW — ii— h       ) 

10K  Vtv/ 


-10 


10K 


k2N3905 
1N482 


C 


i 


-5 


.2N3905 
->OUT 


IK 


-  GND 


] 


■82- 


A.T.C.   LEVEL   SHIFTER    1469-156 


2> 


^3 


«> 


^ 


10> 


^U 


14> 


18 


-10 


1/2A 


A.22> 


.47Mf 
25v 

GND 


.47Mf 
25v 


20> 


^15 


->-10 


10>f 
35  w 


-^GNO 


35v 


^-5 


Figure  30.   Level  Shifter  1469-156 


J 

too 

;  °ui 
5  t-iy 

"ill 

-   g^o 

5    <->b 


B 


5 

x 


if. 

if 

l"°58 

JUS  u.  _i  ?cnj 

ffg§Se 

o2J  in-- 

"■sea  »a 
?l8  i 

5.  i 1  o2 

?|<  2 


0© 


IS  I  So 


$ 


X 

2 


-83- 


<s)       0 


g      §        ll      I 


I    i 


l§    § 


§     l§    § 


—         o 


3T^0 


!  T^=e 


Trio 


I- 


I      W»    ll*! 


i  T^e 


eg 


TNe 


»R0 


8- 


!        1 1  " 


i- 


f  I© 


[6   [£* 


V*r    »  »  H> 


'-»- 


in  »— vv>.-4    W 


^||© 


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3T 


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spH3 


<  -*^*»  ♦  » 


_5j 


8- 


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A. 

10 


11 


to 


^4 


■3" 


-»- 


'IT  1  IT  s  ,TT  s  IT  1  TT"  1  -jf  i  IT"  1  'IT 


d 


to  *  to    to 


*_L 


*4- 


s 

A 

w 

2 

p 


■B._L 

5!' 


Figure  31.   One  Shot  Buffer  1469-159 


1469-161   ~*0    INPUT  NAND 


-81+- 


*1>-| 


,14 


J2_ 


►12- 


^oj. 


ii 


3   ! 


s  ! 


18! 


J*4- 


J^ 


3E 

.IS 


O  GNO 


GNO 


SUPPLY    VOLTAGE     „   .        .*<? 

i_5w\  21  O       ^Ai       f         O    O- 


FILTEHED    VOLTAGE 
OUT 


B   O- 


«>-5v 


NOTES 

(T)  JUMPERS    ALLOW    POSITIVE    OR    NEGATIVE    OPERATION 
2.   ALL    CIRCUITS     TEXAS     INSTRUMENTS     SN7400N 


Figure  32.   General  2- Input  Nand  1469-161 


1469-162    THREE    INPUT   NA'ir 


i 

of 


I _J 

I 1 


14 


Ji 


J2. 


10 


11 


w 


15 


20 


19 


18 


17 


16 


*E1 


33h 


33>] 


33>] 


5*h 


^2 


33h 


35>] 


r 


32>] 


GND  • 


A      O- 


Z    o- 
1     o- 


(-5v) 


FILTERED  VOLTAGE 
OUT 


L  22  © 
SUPPLY  VOLTAGE 


21 
Y     O 


2      O- 


B    o- 


10 


o   o- 

t_f 

© 


.47 
25v 


© 

n 

-o   o- 


-O  GNO 


.47 
25  v 


-t>-5v 


NOTES 


®   JUMPERS    ALLOW    POSITIVE     OR    NEGATIVE    OPERATION 
2.    ALL    CIRCUITS    TEXAS     INSTRUMENTS     SN7410N 

Figure   33.      General  3- Input  Nand     lk69-l62 


1469-173    FILTER 


-86- 


IN  o- 


1 

0 

0 

-5 

330ft 

— WV/       ♦ 


1.5K 


-o  OUT 


.47/if 
25  v 


1 

0 

0 

-5 

NOTES 

1.  ALL    RESISTORS    1/4  W  ,  5  %  . 

2.  SEE    NEXT    PAGE    FOR     PIN    CONNECTIONS 

1469-173     FILTER 


B    o- 


C    o- 


D    O- 


E    o- 


L    o- 


N    o- 


P    o- 


S    o- 


T    o- 


V    o- 


w    o- 


A     O 
22  o 


GND 


19  o 


-5 


-o     1 


-o     2 


-o     3 


-o     5 


-o     6 


-O     8 


-o     9 


-o     10 


-O     11 


-o    12 


-o    13 


-o     14 


-o    15 


-o    16 


-o    17 


-o    18 


Figure  3^.   Switch  Filter  1^69-173 


ATC    LOGIC  TO  VIDEO  CONVERTER    1469-175 


-87- 


+  10  *- 


IN> 


10K 


-)!- 


47  pf 


36  K 


5%,1/2W 


2N3642 


-5 


(3) 
I1N914B 


2N706A 


i>         • 


75  ± 


■>  OUT  (+l.5w  ) 


1N995 


-±  NOTE 


ALL   RESISTORS    1/4  W,  5% 
UNLESS  NOTED. 


> 


17 


W 


■» 


> 


12 


B 


■> 


>^ 


* 


> 


D 


^ 


+  10> 


GND> 


-5> 


•>  +10 


4 *-5 


Figure  35.   Logic  to  Video  Converter  1^69-175 


ATC    INDICATOR    1469-176 


-88- 


in  y — wC — PT  j 


> 


> 


> 


> 


> 


11 


B 


D 


220  ft 


NOTES 

1.  ALL   RESISTORS  1/4  W,  5% 

2.  ALL    TRANSISTORS  2N3642 

3.  BULBS    6v/40ma   (SAME  AS  1469-115) 

4.  SOCKETS   FOR    BULBS 


> 


13 


> 


16 


> 


18 


> 


21 


H 


5> 


22 


GND>-i- 


1/2A 


-*-5 


2.2  Mf 
25v 


GND 


Figure  36.   Indicator  1^69-176 


ATC   VIDEO    TO    LOGIC    CONVERTER    1469- 177A 


IN  >- 


ion 


-L-  1CV 
35v 


+  10 


001Mf 


4.7K 
250pf 


* — wv — * 
100  n 

2.2K 


c 


.i <v^v <► 

IK 


IN  >- 


2N709 


3.9K 


2N967 


,.47  Vi  1N462 
-25v2iTI51    " 


ion 


•10 


2N967 


35v 


-^OUT 


->  OUT 


^  tl^  %  1N914B^  510 
25v    n 


-5 


NOTES 


l.ALL    RESISTORS    1/4  W,  5% 
UNLESS   SPECIFIED. 

(2)  DIODES   AS  THRESHOLD  REQUIRES 


IN  >- 


12 


11 


->0UT 


v      20      1/2A 

+  10  >— — — ^v- 


21       1'2A 
-5>— - 'Vr- 


-10  > 


??       1/2A 

-= — V- 


GND  >- 


A.Z 


X 
X 


t — ►  -10 


.47 

25v 


10Mf 
35v 


.47 
25v 


lOuf 
35v 


1 »•  +10 


.47 

25v 


10Mf 
35v 


GND 


Figure  37-   Video  to  Logic  Converter  1U69-177A 


ATC   +lv    GENERATOR/MODE   SWITCH    1469-178 


CIRCUITS   ABB 


+  10  «• 


.  10K 

IN  > » — vw 


>0UT 
(+2v) 


■90- 


CIRCUITS   cao 


+  10 


150ft 
2W 


2N1308 


47ft(2)  " T >0UT(  +  1 

i-  -47mt       T96 

N  25v   4  e    IK     _L  30Mf 

$  ^P    15v 

<> * i 1       »  GND 


v) 


2> 


?> 


+  10 


A,Z,1> 


(+2v) 


>D 


NOTES 

l.ALL   RESISTORS   1/4  W  , 
5%   UNLESS   SPECIFIED 
2.2  CIRCUITS   EACH   PER  CARD 


B 


(+2v) 


»K 


(+lv) 


»P 


D 


(+lv) 


■>v 


+  10 


Figure  38.   +1  Volt  Power  Supply  /Mode  Sv/itch  1U69-I78 


r-i 

I 

cn 

CD 


UJ 

h- 
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a: 

UJ 
CL 

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£.0 


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CVJ 


-*- 


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C\J 
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10 

s 

01 


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-w- 


C\J 

oj 


O  in 


^« 


^H> 


< 

—■  > 
O  <  ir>  -• 
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N  ■ 


in 


O 
O 

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o 
o 

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a.  cn 
in     t>- 

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JWV-hi 


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3 
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if)  ^ 


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co 

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to 
cr 

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cn 

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Figure  3^*.   Pen  Shaper  and  Gate   1469-179 


■92- 


Q 
UJ 


O 
00 


ID 


or 

lxl 

o 

Q 
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O 
UJ 
Q 

> 


3 
Q_ 

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ro 

o 

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Figure   1+0.      3- Input  Video  Adder     ll+69-l80 


1469-181-20    4-INPUT    NAND 


A l 

B  2 

C  3 

D  4 

E  5 

F  6 

H  — f —  7 


J 
K 
L 
M 
N 
P 
R 

S 

T 
U 
V 


r_ 


L 
2 

3 
4 
5 
6 

7 

1 
2 
3 
4 


w  — 

—  5 

X 

Y  < 

b 

' —  7 

V 


n 


j 


r 


L. 


V 


n 


j 


V7 


"1 


L. 


V 


JTL 


J 


14- 
13- 
12- 
11- 
-10- 

-  9  - 

-  8  - 

14- 
-13- 
-12- 

11- 
-10- 

-  9  - 

-  8  - 

14- 

-13- 

-12- 

11- 

10- 

-  9- 
-8  - 


GND  Z 


1 
2 
3 
4 
5 
6 
7 

8 

9 

10 

11 

12 

13 

14 

15 
16 
17 
18 
19 
20 
21 


22-5 


NOTES 

1.  CIRCUITS    ARE    TEXAS    INSTRUMENTS    SN7420N 

Figure  1+1.   General  1+- Input  Nand  l*+69- 181-20 


1469-181-70  J-K   FLIP-FLOP 


A l 

B 2 

C 3 

D  4 

E  5 

F  6 

H  — T —  7 


J 
K 
L 
M 

N 
P 
R 


S 

T 
U 
V 

w 

X 
Y 


;nd  z 


t2 


£2 


CLK      K 


L. 

r- 


i 


£} 


CLK 


L. 


>> 


I-- 


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s: 


i 


t 


CLK 


14- 
-13- 

12- 
■11- 

10- 
■  9  ■ 
•8 


14- 
•13- 
12- 
11- 
•10- 
9  ■ 
8  ■ 


14- 
13- 
12- 

■11- 
10- 
9  ■ 

•  8  • 


1/2  A 


2.2 


NOTES 


8 

9 
10 
11 
12 
13 
14 


15 
16 
17 

•18 
19 
20 

•21 


•22-5 


-9k- 


ALL   CIRCUITS  TEXAS    INSTRUMENTS    SN7470N 


Figure  h2.      General  J-K  Flip  Flop  lU69-l8l-70 


1469-184    VOLTAGE    CONTROLLED    OSCILLATOR 


-95- 


iFC     \l 


"1 
2  i 


CLK  <  B     "q     l 


„    :/2  a 


^21    '!• 


T~!°    1 


4.2 


-r — "-s 

J 


■10 


CLK  <■ 
CLK  <- 


E      I 


^ 


L 


1 


1  ALL    RESISTORS   1/4  V»  .  5% 

2  INTEGRATED    AMPLIFIERS    ARE    FAlRCMILO 

3  ALL    CAPACITORS     IN    *!     JNLESS    NOTED 


GMD 


are  43.   Voltage  Controlled  Oscillator 


-96- 


2  *  *- 

m   O  3 

->  X.  o 


m 


z 
o 
hS 

<_>  CD 

H 

5> 
i  < 

?^ 

Q.  </> 
<  5 

o  P 
o  *" 

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iuj  > 


i<r>- 


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«    9    S    S    S      |§       |? 


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it       _i       Z       z      a.       a:      v>      >- 


14444 


q 


44444 


-^     <«     n 


§       '    -    -a   -s   i   -a 

>        »        *        > 

in       r»       O       O 


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PI 


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r!-<i" 


-rH* 


-<u. 


-Ii_<h  8 


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-1— 4-c*    ?' 


-:-<2 


O' 


O 


Q 


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<*  s , 


Figure  U4.   Main  Junction  Box 


Figure  h^>.      Display  Junction  Box 


K> 


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-98- 


UJ 

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CE 
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O  UJ  \  o        \< 

CVJ  CC  uj 

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a33ds  on 

CI33dS  IH 

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3 
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\k     \j/    \k 

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uj     oo     y 
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a. 
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ti 


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en 

-_l 

00  0. 
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en 
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T  < 

o 

^H  (\J 


Figure  1+6.   Circuit  Breaker  Panel 


MODULAR    POWER   SUPPLIES -ATC 


■99- 


SORENSEN 
OSA10-3  7 


2     1     *     5     6     7 


AMPH 
67-OJE     14-9S 


L 


JUNCTION    N_ 
BOX    C_ 


>^ 


SORENSfN 

OS*  10-57 


1     2      3    4     '->     6  M 


SO»ENS£N 
0SA10-2  2 


12     3    4    5     6    7 


JL 


AC  CORD.   3  COND   #16 
«MTE 


0 


SORENSEN 
OS*  10-2  2 


12     3    4    3     6    7 


J29B 

TO  MAIN    >- 

JUNCTION     w 

B0» 


>- 


SORENSEN 
0SA28-2O 


12     3    4    5     6    7 


CT 


SORENSEN 
OSA  28-20 


12     3    4    5    6    7 


r 


AC  CORD.  3  COM)   » 16 
WHfTE 


ct 


Figure  h'J .      Modular  Power  Supplies 


o 

<f 


I 
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X 

u 
j- 

$ 
in 

u 

t-' 
< 


^<r 


Urn  ^        «H 

52  S ! 8 -| 


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5 

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im 

o 

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Q    .  -=! 
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or 

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a.  _i 


03  ol 

<  01 

o< 
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a.  on 


Figure  U8.   Switch  Panel 


rtNio»«*Na)si 


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Figure  1+9 .      Cable  Details 


-102- 


A3.0  CAED  RACK  LISTS 


CARD  RACK  A 


1.  Switch  Matrix 

2.  Indicator 

3.  Total  Erase  Control 

h.  Logic  to  Video  Converter 

5 .  Blank 

6.  2- Input  Nand 

7.  2- Input  Nand 

8.  +1  Volt  Generator /Mode  Switch 

9.  Blank 

10.  Logic  to  Video  Converter 

11 .  Blank 

12.  Blank 

13.  2- Input  Nand 
1^ .  Blank 

15.  Pen  Pulse  Shaping  Circuit 

16 .  Blank 

17.  Video  to  Logic  Converter 

18.  Blank 

19.  3- Input  Video  Adder 

20.  3- Input  Video  Adder 

21.  3- Input  Video  Adder 


CARD  RACK  B 

1.  Level  Shifter 

2.  Horizontal  Oscillator 
3-  Horizontal  Counter 

h.  Horizontal  Buffer 

5.  9-Bit  Register  and  Coincidence 

6.  2- Input  Nand 

7.  Dual  9-Bit  Register 

8.  9-Bit  Register  and  Coincidence 
9-  2- Input  Nand 

10.  9-Bit  Register  and  Coincidence 

11.  9-Bit  Register  and  Coincidence 

12.  2- Input  Nand 

13 .  Blank 

Ik.  Vertical  Counter 

15.  Vertical  Buffer 

16.  8-Bit  Register  and  Coincidence 

17.  2- Input  Nand 

18.  8-Bit  Register  and  Coincidence 

19.  8-Bit  Register  and  Coincidence 

20.  8-Bit  Register  and  Coincidence 
21. 


-1C&- 


CARD  RACK  C 

1. 

One  Shot  Buffer 

2. 

h- Input  Nand 

3- 

2- Input  Nand 

k. 

3 -Input  Nand 

5. 

R-S  Flip  Flop  and 

2-Bit  Coincidence 

6. 

Indicator 

7- 

R-S  Flip  Flop 

8. 

2- Input  Nand 

9- 

2- Input  Nand 

10. 

3- Input  Nand 

n. 

J-K  Flip  Flop 

12. 

Blank 

13- 

Blank 

14. 

Blank 

15- 

Blank 

16. 

Blank 

17- 

Blank 

18. 

Blank 

19. 

Blank 

20. 

Blank 

21. 

Blank  . 

-1C 

A^.O  OPERATING  PROCEDU1  i'MENTB 

To  operate  the  Tricolor  Cartograph  turr.     tin  circuit  breai 
and  allow  to  warm  up  for  ten  minutes.   Before  using,  all  tracks 
disc  should  be  erased.   This  is  accomplished  by  depressing  the  Outline 
Erase  button  and  the  Color  Erase  button  after  depressing  all  three  color 
selector  buttons.   Adjust  the  Contrast  control  to  the  one  o'clock  position 
and  the  Brightness  control  to  halfway  between  one  and  two  o'clock.   To 
write  in  a  color  with  the  pen,  select  the  desired  color  or  combination  of 
colors  and  depress  the  Write  button.   Now  hold  the  pen  so  that  the  small 
white  pen  marker  spot  appears  on  the  screen.  Depress  the  Enable  button 
on  the  pen  and  it  will  write.   If  no  pen  marker  spot  can  be  seen  the 
Brightness  control  is  set  too  low. 

To  erase  a  color  with  the  pen  repeat  the  above  procedure  but 
depress  the  Erase  Color  button.   The  colors  are  selected  by  the  color 
selector  buttons. 

Writing  or  erasing  an  outline  is  accomplished  in  the  same 
manner  as  above  except  that  the  Draw  Outline  or  Erase  Outline  button  is 
depressed  and  the  color  selector  buttons  have  no  effect. 

To  color,  depress  the  Color  button,  point  the  pen  to  the 
interior  of  the  outline  which  is  to  be  colored  and  depress  the  Enable 
button.   The  color  is  chosen  by  the  color  selector  buttons. 

The  entire  outline  or  all  of  one  color  may  be  erased  at  any 
time  by  depressing  the  Outline  Erase  button  or  the  Color  Erase  button. 
Colors  to  be  erased  are  selected  by  means  of  the  color  selector  buttons. 
The  Outline  Erase  and  Color  Erase  buttons  are  independent  of  all  other 
buttons . 


-106- 

There  are  several  adjustments  that  can  be  made  to  the  Tricolor 
Cartograph.   There  are  numerous  adjustments  for  the  color  monitor  and  the 
video  disc.   These  will  not  be  discussed  here.   Instructions  for  these 
adjustments  may  be  found  in  the  respective  manuals  for  these  units.  Five 
circuits  in  the  Processor  have  adjustments.   They  are:   the  Pen  Shaping 
Circuit,  the  pen  thresholding  amplifier,  the  Video  to  Logic  Converter, 
the  3 -Input  Video  Adders  and  the  Voltage  Controlled  Oscillator. 

The  thresholding  amplifier  should  be  set  at  a  level  which  will 
completely  clip  the  noise  pulses  generated  by  the  monitor  flyback  circuit, 
This  should  be  done  after  the  system  is  thoroughly  warmed  up.   (~  one 
hour) . 

After  the  threshold  circuit  has  been  adjusted  the  pen  shaping 
circuit  should  be  adjusted  so  that  no  extraneous  noise  pulses  appear  on 
the  screen. 

The  Video  to  Logic  Converter  can  be  adjusted  to  respond  only 
to  signals  above  a  certain  threshold  level.   Small  adjustments  in  this 
level  are  made  with  the  potentiometer.   Large  adjustments  require  that 
the  bias  diodes  in  the  circuit  be  changed.   The  pen  threshold  may  be 
set  at  minimum  but  the  outline  threshold  can  only  be  as  low  as  is 
possible  without  picking  up  false  outline  pulses.  Neither  thresholds 
must  not  be  set  so  high  that  ligitimate  pen  or  outline  pulses  are  clipped. 

The  3 -Input  Video  Adders  have  four  gain  adjustments,  one  for 
each  of  the'  3  video  inputs  and  one  for  their  sum.   The  video  from  the 
disc  will  be  in  the  range  0.7  to  1.0  volts.   The  adders  should  be 
adjusted  so  that  each  of  the  inputs  (video,  outline  and  pen),  when  used 
along,  produces  a  1  volt  signal  at  the  output. 


There  are  three  adjustments  to  thi      age  Controlled  Os cilia 
The  zero  adjustment  provides  a  means  of  setting  the  input  t 
to  zero  when  the  incoming  AFC  pulse  is  at  the  normal  rate  (l5,750Hzy  and 
width  (9.5  (isec).  The  frequency  adjustment  capacitor  provides  a  limited 
range  for  adjusting  the  oscillator  frequency  to  8MHz.   Large  fre 
adjustments  must  be  made  by  changing  the  inductance.   The  gain  adjustment 
allows  adjustment  of  the  frequency  shift  for  a  given  input  pulse  width 
change. 


■108- 


BIBIIOGRAPHY 


Barney,  Walter.   "New  Terminals  in  Display  Picture,"  Electronics. 
January  8,  1968.   McGraw  Hill  Book  Co. 

Bycer,  Bernard  B.   Digital  Magnetic  Tape  Recording:   Principles  and 

Computer  Applications.   Hayden  Book  Co.,  Inc.,  New  York,  1965. 

Esch,  J.  W. ,  et  al.   Artrix  Final  Report,  Report  #238  Digital  Computer 
laboratory,  University  of  Illinois,  Urbana,  Illinois, 
June  20,  1967. 

Glasford,  Glenn  M.   Fundamentals  of  Television  Engineering.   McGraw 
Hill  Book  Co.   1955. 

Giles,  James  N.   Fairchild  Semiconductor  linear  Integrated  Circuits 

Applications  Handbook.   Fairchild  Semiconductor,  Mountain  View, 
California,  I967. 

Hendrickson,  Herbert  C.   A  High-Precision  Display  System  for  Command  and 
Control  Information  Display '.      July /August,  I967. 

Howard,  James  N. ,  Ed.   Electronic  Information  Display  Systems.   Spartan 
Books,  Washington,  1963- 

Kiver,  Milton  S.   Color  Television  Fundamentals.   McGraw-Hill  Book  Co. 
New  York,  1964. 

Kubitz,  W.  J.   Quarterly  Technical  Progress  Report,  Digital  Computer 

laboratory,  University  of  Illinois,  Urbana,  Illinois.   October, 

November,  December,  1966.   #COO-l469-0064. 

Also:   January,  February,  March,  1967  COO-II469-OO7I 

July,  August,  September,  1967  COO-1469-0073 

January,  February,  March,  1^68 

Poole,  Harvey  H.   Fundamentals  of  Display  Systems.   Spartan  Books, 
Washington,  I966. 

Richards,  R.  K.   Electronic  Digital  System.   John  Wiley  and  Son,  Inc. 
New  York,  I966. 

Risko,  Frank  D.   "Design  Factors  in  Magnetic  Pulse  Recording."  Electro- 
Technology,  December,  1967- 

Southworth,  Glen  R.   "A  Magnetic  Disc  Video-Scan  Converter,"  a  paper 
presented  at  the  102nd  Technical  Conference  of  the  SMPTE, 
September  17-22,  1967. 


VITA 

William  John  Kubitz  was  born  in  Freeport,  Illinc 
27,  1938.   He  graduated  from  Freeport  High  School  in  1957-   In  196l  he 
received  his  B.S.  in  Engineering  Physics  from  the  University  of  Illinois. 
He  received  his  M.S.  in  Physics  from  Illinois  in  I962.  From  1962  to 
I96U  he  was  a  development  engineer  with  the  General  Electric  Company. 
In  I96U  he  returned  to  the  University  of  Illinois  to  work  toward  a  Ph.D. 
in  Electrical  Engineering.   He  is  a  member  of  the  IEEE. 


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